Some normalizations are unavoidable, such as rounding floating-point
results to the current precision, and reducing fractions to simplest
form. Others, such as simplifying a formula like @expr{a+a} (or @expr{2+3}),
-are done by default but can be turned off when necessary.
+are done automatically but can be turned off when necessary.
When you press a key like @kbd{+} when @expr{2} and @expr{3} are on the
stack, Calc pops these numbers, normalizes them, creates the formula
error form or modulo form), or a vector all of whose
elements are constant.
-@kindex m L
-@pindex calc-limited-simplify-mode
-The @kbd{m L} (@code{calc-limited-simplify-mode}) command does limited
+@kindex m I
+@pindex calc-basic-simplify-mode
+The @kbd{m I} (@code{calc-basic-simplify-mode}) command does some basic
simplifications for all formulas. This includes many easy and
fast algebraic simplifications such as @expr{a+0} to @expr{a}, and
@expr{a + 2 a} to @expr{3 a}, as well as evaluating functions like
are rounded to the nearest integer and then clipped; other kinds of
results (after the default simplifications) are left alone.
-@kindex m D
-@pindex calc-default-simplify-mode
-The @kbd{m D} (@code{calc-default-simplify-mode}) mode does standard
+@kindex m A
+@pindex calc-alg-simplify-mode
+The @kbd{m A} (@code{calc-alg-simplify-mode}) mode does standard
algebraic simplifications. @xref{Algebraic Simplifications}.
@kindex m E
@pindex calc-ext-simplify-mode
-The @kbd{m E} (@code{calc-ext-simplify-mode}) mode does ``extended''
-algebraic simplification, as by the @kbd{a e} (@code{calc-simplify-extended})
-command. @xref{Unsafe Simplifications}.
+The @kbd{m E} (@code{calc-ext-simplify-mode}) mode does ``extended'', or
+``unsafe'', algebraic simplification. @xref{Unsafe Simplifications}.
@kindex m U
@pindex calc-units-simplify-mode
The @kbd{m U} (@code{calc-units-simplify-mode}) mode does units
-simplification; it applies the command @kbd{u s}
-(@code{calc-simplify-units}), which in turn
-is a superset of @kbd{a s}. In this mode, variable names which
+simplification. @xref{Simplification of Units}. These include the
+algebraic simplifications, plus variable names which
are identifiable as unit names (like @samp{mm} for ``millimeters'')
are simplified with their unit definitions in mind.
only when certain values are integers (such as @samp{(x^y)^z}
shown above).
-Another command that makes use of declarations is @kbd{a s}, when
-simplifying equations and inequalities. It will cancel @code{x}
+Calc's algebraic simplifications also make use of declarations when
+simplifying equations and inequalities. They will cancel @code{x}
from both sides of @samp{a x = b x} only if it is sure @code{x}
is non-zero, say, because it has a @code{pos} declaration.
To declare specifically that @code{x} is real and non-zero,
The @code{dpos} function checks for positive (but nonzero) reals.
The @code{dneg} function checks for negative reals. The @code{dnonneg}
function checks for nonnegative reals, i.e., reals greater than or
-equal to zero. Note that the @kbd{a s} command can simplify an
-expression like @expr{x > 0} to 1 or 0 using @code{dpos}, and that
-@kbd{a s} is effectively applied to all conditions in rewrite rules,
-so the actual functions @code{dpos}, @code{dneg}, and @code{dnonneg}
+equal to zero. Note that Calc's algebraic simplifications, which are
+effectively applied to all conditions in rewrite rules, can simplify
+an expression like @expr{x > 0} to 1 or 0 using @code{dpos}.
+So the actual functions @code{dpos}, @code{dneg}, and @code{dnonneg}
are rarely necessary.
@ignore
The @code{deven} function returns 1 if its argument is known to be
an even integer (or integer-valued float); it returns 0 if its argument
is known not to be even (because it is known to be odd or a non-integer).
-The @kbd{a s} command uses this to simplify a test of the form
+Calc's algebraic simplifications use this to simplify a test of the form
@samp{x % 2 = 0}. There is also an analogous @code{dodd} function.
@ignore
rule, it first matches the pattern as usual. It then substitutes
@samp{#1}, @samp{#2}, etc., in the conditions, if any. Next, the
conditions are simplified and evaluated in order from left to right,
-as if by the @w{@kbd{a s}} algebra command (@pxref{Simplifying Formulas}).
+using the algebraic simplifications (@pxref{Simplifying Formulas}).
Each result is true if it is a nonzero number, or an expression
that can be proven to be nonzero (@pxref{Declarations}). If the
results of all conditions are true, the expression (such as
@item BinSimp@var{w}
Binary-integer simplification mode; word size @var{w} (@kbd{m B}, @kbd{b w}).
-@item LimSimp
-Limited simplification mode (@kbd{m L}).
+@item BasicSimp
+Basic simplification mode (@kbd{m I}).
@item ExtSimp
Extended algebraic simplification mode (@kbd{m E}).
the form @expr{x} plus a multiple of @cpiover{2} are also simplified.
Calc includes similar formulas for @code{cos} and @code{tan}.
-The @kbd{a s} command knows all angles which are integer multiples of
+Calc's algebraic simplifications know all angles which are integer multiples of
@cpiover{12}, @cpiover{10}, or @cpiover{8} radians. In Degrees mode,
analogous simplifications occur for integer multiples of 15 or 18
degrees, and for arguments plus multiples of 90 degrees.
Use @kbd{a v} if you want the variables to ignore their stored values.
If you give a numeric prefix argument of 2 to @kbd{a v}, it simplifies
-as if in Algebraic Simplification mode. This is equivalent to typing
-@kbd{a s}; @pxref{Simplifying Formulas}. If you give a numeric prefix
-of 3 or more, it uses Extended Simplification mode (@kbd{a e}).
+using Calc's algebraic simplifications; @pxref{Simplifying Formulas}.
+If you give a numeric prefix of 3 or more, it uses Extended
+Simplification mode (@kbd{a e}).
If you give a negative prefix argument @mathit{-1}, @mathit{-2}, or @mathit{-3},
it simplifies in the corresponding mode but only works on the top-level
are mapped, the direction of the second inequality is reversed to
match the first: Using @kbd{a M +} on @samp{a < b} and @samp{a > 2}
reverses the latter to get @samp{2 < a}, which then allows the
-combination @samp{a + 2 < b + a}, which the @kbd{a s} command can
-then simplify to get @samp{2 < b}.
+combination @samp{a + 2 < b + a}, which the algebraic simplifications
+can reduce to @samp{2 < b}.
Using @kbd{a M *}, @kbd{a M /}, @kbd{a M n}, or @kbd{a M &} to negate
or invert an inequality will reverse the direction of the inequality.
@xref{Rewrite Rules}.
@xref{Simplification Modes}, for commands to control what level of
-simplification occurs automatically. Normally only the default
-algebraic simplifications occur. If you have turned on a
-simplification mode which does not do these default simplifications,
-you can still perform them on a formula with the @kbd{a s} command.
+simplification occurs automatically. Normally the algebraic
+simplifications described below occur. If you have turned on a
+simplification mode which does not do these algebraic simplifications,
+you can still apply them to a formula with the @kbd{a s}
+(@code{calc-simplify}) [@code{simplify}] command.
There are some simplifications that, while sometimes useful, are never
done automatically. For example, the @kbd{I} prefix can be given to
@kbd{a s}; the @kbd{I a s} command will change any trigonometric
function to the appropriate combination of @samp{sin}s and @samp{cos}s
before simplifying. This can be useful in simplifying even mildly
-complicated trigonometric expressions. For example, while @kbd{a s}
-can reduce @samp{sin(x) csc(x)} to @samp{1}, it will not simplify
-@samp{sin(x)^2 csc(x)}. The command @kbd{I a s} can be used to
+complicated trigonometric expressions. For example, while the algebraic
+simplifications can reduce @samp{sin(x) csc(x)} to @samp{1}, they will not
+simplify @samp{sin(x)^2 csc(x)}. The command @kbd{I a s} can be used to
simplify this latter expression; it will transform @samp{sin(x)^2
csc(x)} into @samp{sin(x)}. However, @kbd{I a s} will also perform
some ``simplifications'' which may not be desired; for example, it
@menu
-* Limited Simplifications::
+* Basic Simplifications::
* Algebraic Simplifications::
* Unsafe Simplifications::
* Simplification of Units::
@end menu
-@node Limited Simplifications, Algebraic Simplifications, Simplifying Formulas, Simplifying Formulas
-@subsection Limited Simplifications
+@node Basic Simplifications, Algebraic Simplifications, Simplifying Formulas, Simplifying Formulas
+@subsection Basic Simplifications
@noindent
-@cindex Limited simplifications
-This section describes a limited set of simplifications. These, as
-well as those described in the next section, are normally applied to
-all results. You can type @kbd{m L} to restrict the simplifications
-done on the stack to this limited set.
+@cindex Basic simplifications
+This section describes basic simplifications which Calc performs in many
+situations. For example, both binary simplifications and algebraic
+simplifications begin by performing these basic simplifications. You
+can type @kbd{m I} to restrict the simplifications done on the stack to
+these simplifications.
The most basic simplification is the evaluation of functions.
For example, @expr{2 + 3} is evaluated to @expr{5}, and @expr{@tfn{sqrt}(9)}
operator) does not evaluate all of its arguments, and @code{evalto}
does not evaluate its lefthand argument.
-Most commands apply at least these limited simplifications to all
+Most commands apply at least these basic simplifications to all
arguments they take from the stack, perform a particular operation,
then simplify the result before pushing it back on the stack. In the
common special case of regular arithmetic commands like @kbd{+} and
(the arguments being simplified first as part of the process, as
described above).
-Even the limited set of simplifications are too numerous to describe
+Even the basic set of simplifications are too numerous to describe
completely here, but this section will describe the ones that apply to the
major arithmetic operators. This list will be rather technical in
nature, and will probably be interesting to you only if you are
special cases described below. Some algebra programs always
rearrange terms into a canonical order, which enables them to
see that @expr{a b + b a} can be simplified to @expr{2 a b}.
-Calc assumes you have put the terms into the order you want
-and generally leaves that order alone, with the consequence
-that formulas like the above will only be simplified if you
-explicitly give the @kbd{a s} command. @xref{Algebraic
-Simplifications}.
+If you are using Basic Simplification mode, Calc assumes you have put
+the terms into the order you want and generally leaves that order alone,
+with the consequence that formulas like the above will only be
+simplified if you explicitly give the @kbd{a s} command.
+@xref{Algebraic Simplifications}.
Differences @expr{a - b} are treated like sums @expr{a + (-b)}
for purposes of simplification; one of the default simplifications
is simplified to @expr{a + 2 b + c}, but @expr{a + b + c + b}
is not simplified. The reason is that comparing all terms of a
sum with one another would require time proportional to the
-square of the number of terms; Calc relegates potentially slow
-operations like this to commands that have to be invoked
-explicitly, like @kbd{a s}.
+square of the number of terms; Calc omits potentially slow
+operations like this in basic simplification mode.
Finally, @expr{a + 0} and @expr{0 + a} are simplified to @expr{a}.
A consequence of the above rules is that @expr{0 - a} is simplified
Functions like @code{sin} and @code{arctan} generally don't have
any default simplifications beyond simply evaluating the functions
-for suitable numeric arguments and infinity. The @kbd{a s} command
-described in the next section does provide some simplifications for
-these functions, though.
+for suitable numeric arguments and infinity. The algebraic
+simplifications described in the next section do provide some
+simplifications for these functions, though.
One important simplification that does occur is that
@expr{@tfn{ln}(@tfn{e})} is simplified to 1, and @expr{@tfn{ln}(@tfn{e}^x)} is
@expr{!!x} to @expr{x}, this would not be valid in general because
@expr{!!2} is 1, not 2.
-Most other Calc functions have few if any default simplifications
+Most other Calc functions have few if any basic simplifications
defined, aside of course from evaluation when the arguments are
suitable numbers.
-@node Algebraic Simplifications, Unsafe Simplifications, Limited Simplifications, Simplifying Formulas
+@node Algebraic Simplifications, Unsafe Simplifications, Basic Simplifications, Simplifying Formulas
@subsection Algebraic Simplifications
@noindent
@cindex Algebraic simplifications
@kindex a s
-@kindex I a s
-@kindex H a s
-@pindex calc-simplify
-@tindex simplify
+@kindex m A
This section describes all simplifications that are performed by
-the default algebraic simplification mode. If you have switched to a different
-simplification mode, you can switch back with the @kbd{m D} command.
-Even in other simplification modes, the @kbd{a s} command will use
-these algebraic simplifications to simplifies the formula.
+the algebraic simplification mode, which is the default simplification
+mode. If you have switched to a different simplification mode, you can
+switch back with the @kbd{m A} command. Even in other simplification
+modes, the @kbd{a s} command will use these algebraic simplifications to
+simplify the formula.
There is a variable, @code{AlgSimpRules}, in which you can put rewrites
to be applied. Its use is analogous to @code{EvalRules},
@samp{@w{a r} AlgSimpRules} with an infinite repeat count on the whole
expression being simplified, then it traverses the expression applying
the built-in rules described below. If the result is different from
-the original expression, the process repeats with the limited
+the original expression, the process repeats with the basic
simplifications (including @code{EvalRules}), then @code{AlgSimpRules},
then the built-in simplifications, and so on.
Also, terms of sums are combined by the distributive law, as in
@expr{x + y + 2 x} to @expr{y + 3 x}. This always occurs for
-adjacent terms, but @kbd{a s} compares all pairs of terms including
-non-adjacent ones.
+adjacent terms, but Calc's algebraic simplifications compare all pairs
+of terms including non-adjacent ones.
@tex
\bigskip
@cindex Unsafe simplifications
@cindex Extended simplification
@kindex a e
+@kindex m E
@pindex calc-simplify-extended
@ignore
@mindex esimpl@idots
@end ignore
@tindex esimplify
-The @kbd{a e} (@code{calc-simplify-extended}) [@code{esimplify}] command
-is like @kbd{a s}
-except that it applies some additional simplifications which are not
-``safe'' in all cases. Use this only if you know the values in your
-formula lie in the restricted ranges for which these simplifications
-are valid. The symbolic integrator uses @kbd{a e};
-one effect of this is that the integrator's results must be used with
-caution. Where an integral table will often attach conditions like
-``for positive @expr{a} only,'' Calc (like most other symbolic
-integration programs) will simply produce an unqualified result.
+Calc is capable of performing some simplifications which may sometimes
+be desired but which are not ``safe'' in all cases. The @kbd{a e}
+(@code{calc-simplify-extended}) [@code{esimplify}] command
+applies the algebraic simplifications as well as these extended, or
+``unsafe'', simplifications. Use this only if you know the values in
+your formula lie in the restricted ranges for which these
+simplifications are valid. You can use Extended Simplification mode
+(@kbd{m E}) to have these simplifications done automatically.
+
+The symbolic integrator uses these extended simplifications; one effect
+of this is that the integrator's results must be used with caution.
+Where an integral table will often attach conditions like ``for positive
+@expr{a} only,'' Calc (like most other symbolic integration programs)
+will simply produce an unqualified result.
Because @kbd{a e}'s simplifications are unsafe, it is sometimes better
to type @kbd{C-u -3 a v}, which does extended simplification only
In fact, @kbd{C-u -3 j v} allows you to target extended simplification
to any specific part of a formula.
-The variable @code{ExtSimpRules} contains rewrites to be applied by
-the @kbd{a e} command. These are applied in addition to
+The variable @code{ExtSimpRules} contains rewrites to be applied when
+the extended simplifications are used. These are applied in addition to
@code{EvalRules} and @code{AlgSimpRules}. (The @kbd{a r AlgSimpRules}
step described above is simply followed by an @kbd{a r ExtSimpRules} step.)
-Following is a complete list of ``unsafe'' simplifications performed
-by @kbd{a e}.
+Following is a complete list of the ``unsafe'' simplifications.
@tex
\bigskip
@end tex
Inverse trigonometric or hyperbolic functions, called with their
-corresponding non-inverse functions as arguments, are simplified
-by @kbd{a e}. For example, @expr{@tfn{arcsin}(@tfn{sin}(x))} changes
+corresponding non-inverse functions as arguments, are simplified.
+For example, @expr{@tfn{arcsin}(@tfn{sin}(x))} changes
to @expr{x}. Also, @expr{@tfn{arcsin}(@tfn{cos}(x))} and
@expr{@tfn{arccos}(@tfn{sin}(x))} both change to @expr{@tfn{pi}/2 - x}.
These simplifications are unsafe because they are valid only for
Common factors are canceled from products on both sides of an
equation, even if those factors may be zero: @expr{a x / b x}
to @expr{a / b}. Such factors are never canceled from
-inequalities: Even @kbd{a e} is not bold enough to reduce
-@expr{a x < b x} to @expr{a < b} (or @expr{a > b}, depending
+inequalities: Even the extended simplifications are not bold enough to
+reduce @expr{a x < b x} to @expr{a < b} (or @expr{a > b}, depending
on whether you believe @expr{x} is positive or negative).
The @kbd{a M /} command can be used to divide a factor out of
both sides of an inequality.
@subsection Simplification of Units
@noindent
-The simplifications described in this section are applied by the
-@kbd{u s} (@code{calc-simplify-units}) command. These are in addition
-to the regular @kbd{a s} (but not @kbd{a e}) simplifications described
-earlier. @xref{Basic Operations on Units}.
+The simplifications described in this section (as well as the algebraic
+simplifications) are applied when units need to be simplified. They can
+be applied using the @kbd{u s} (@code{calc-simplify-units}) command, or
+will be done automatically in Units Simplification mode (@kbd{m U}).
+@xref{Basic Operations on Units}.
The variable @code{UnitSimpRules} contains rewrites to be applied by
-the @kbd{u s} command. These are applied in addition to @code{EvalRules}
+units simplifications. These are applied in addition to @code{EvalRules}
and @code{AlgSimpRules}.
Scalar mode is automatically put into effect when simplifying units.
@vindex IntegSimpRules
Another set of rules, stored in @code{IntegSimpRules}, are applied
-every time the integrator uses @kbd{a s} to simplify an intermediate
-result. For example, putting the rule @samp{twice(x) := 2 x} into
-@code{IntegSimpRules} would tell Calc to convert the @code{twice}
-function into a form it knows whenever integration is attempted.
+every time the integrator uses algebraic simplifications to simplify an
+intermediate result. For example, putting the rule
+@samp{twice(x) := 2 x} into @code{IntegSimpRules} would tell Calc to
+convert the @code{twice} function into a form it knows whenever
+integration is attempted.
One more way to influence the integrator is to define a function with
the @kbd{Z F} command (@pxref{Algebraic Definitions}). Calc's
you can use @code{IntegAfterRules}. This is an extra rule set that
runs after the main integrator returns its result; basically, Calc does
an @kbd{a r IntegAfterRules} on the result before showing it to you.
-(It also does an @kbd{a s}, without @code{IntegSimpRules}, after that
-to further simplify the result.) For example, Calc's integrator
+(It also does algebraic simplifications, without @code{IntegSimpRules},
+after that to further simplify the result.) For example, Calc's integrator
sometimes produces expressions of the form @samp{ln(1+x) - ln(1-x)};
the default @code{IntegAfterRules} rewrite this into the more readable
form @samp{2 arctanh(x)}. Note that, unlike @code{IntegRules},
@samp{sum(a_k, k, 0, 2 n, n)} produces @samp{a_0 + a_n + a_(2 n)}.
Calc computes the number of iterations using the formula
@samp{1 + (@var{high} - @var{low}) / @var{step}}, which must,
-after simplification as if by @kbd{a s}, evaluate to an integer.
+after algebraic simplification, evaluate to an integer.
If the number of iterations according to the above formula does
not come out to an integer, the sum is invalid and will be left
the rule is accepted. Once @var{old} has been successfully matched
to the target expression, @var{cond} is evaluated (with all the
meta-variables substituted for the values they matched) and simplified
-with @kbd{a s} (@code{calc-simplify}). If the result is a nonzero
+with Calc's algebraic simplifications. If the result is a nonzero
number or any other object known to be nonzero (@pxref{Declarations}),
the rule is accepted. If the result is zero or if it is a symbolic
formula that is not known to be nonzero, the rule is rejected.
@end ignore
@tindex evalsimp
The formula @expr{x} has meta-variables substituted in the usual
-way, then algebraically simplified as if by the @kbd{a s} command.
+way, then algebraically simplified.
@item evalextsimp(x)
@ignore
@end ignore
@tindex let
The expression @expr{x} is evaluated with meta-variables substituted.
-The @kbd{a s} command's simplifications are @emph{not} applied by
+The algebraic simplifications are @emph{not} applied by
default, but @expr{x} can include calls to @code{evalsimp} or
@code{evalextsimp} as described above to invoke higher levels
-of simplification. The
-result of @expr{x} is then bound to the meta-variable @expr{v}. As
-usual, if this meta-variable has already been matched to something
-else the two values must be equal; if the meta-variable is new then
-it is bound to the result of the expression. This variable can then
-appear in later conditions, and on the righthand side of the rule.
+of simplification. The result of @expr{x} is then bound to the
+meta-variable @expr{v}. As usual, if this meta-variable has already
+been matched to something else the two values must be equal; if the
+meta-variable is new then it is bound to the result of the expression.
+This variable can then appear in later conditions, and on the righthand
+side of the rule.
In fact, @expr{v} may be any pattern in which case the result of
evaluating @expr{x} is matched to that pattern, binding any
meta-variables that appear in that pattern. Note that @code{let}
@cindex @code{AlgSimpRules} variable
@vindex AlgSimpRules
Suppose you want @samp{sin(a + b)} to be expanded out not all the time,
-but only when @kbd{a s} is used to simplify the formula. The variable
-@code{AlgSimpRules} holds rules for this purpose. The @kbd{a s} command
-will apply @code{EvalRules} and @code{AlgSimpRules} to the formula, as
-well as all of its built-in simplifications.
+but only when algebraic simplifications are used to simplify the
+formula. The variable @code{AlgSimpRules} holds rules for this purpose.
+The @kbd{a s} command will apply @code{EvalRules} and
+@code{AlgSimpRules} to the formula, as well as all of its built-in
+simplifications.
Most of the special limitations for @code{EvalRules} don't apply to
@code{AlgSimpRules}. Calc simply does an @kbd{a r AlgSimpRules}
-command with an infinite repeat count as the first step of @kbd{a s}.
-It then applies its own built-in simplifications throughout the
-formula, and then repeats these two steps (along with applying the
-default simplifications) until no further changes are possible.
+command with an infinite repeat count as the first step of algebraic
+simplifications. It then applies its own built-in simplifications
+throughout the formula, and then repeats these two steps (along with
+applying the default simplifications) until no further changes are
+possible.
@cindex @code{ExtSimpRules} variable
@cindex @code{UnitSimpRules} variable
@tindex usimplify
The @kbd{u s} (@code{calc-simplify-units}) [@code{usimplify}] command
simplifies a units
-expression. It uses @kbd{a s} (@code{calc-simplify}) to simplify the
+expression. It uses Calc's algebraic simplifications to simplify the
expression first as a regular algebraic formula; it then looks for
features that can be further simplified by converting one object's units
to be compatible with another's. For example, @samp{5 m + 23 mm} will
@item s D
Edit @code{Decls}. @xref{Declarations}.
@item s E
-Edit @code{EvalRules}. @xref{Limited Simplifications}.
+Edit @code{EvalRules}. @xref{Basic Simplifications}.
@item s F
Edit @code{FitRules}. @xref{Curve Fitting}.
@item s G
All current modes apply when an @samp{=>} operator is computed,
including the current simplification mode. Recall that the
-formula @samp{x + y + x} is not handled by Calc's default
-simplifications, but the @kbd{a s} command will reduce it to
-the simpler form @samp{y + 2 x}. You can also type @kbd{m A}
-to enable an Algebraic Simplification mode in which the
-equivalent of @kbd{a s} is used on all of Calc's results.
-If you enter @samp{x + y + x =>} normally, the result will
-be @samp{x + y + x => x + y + x}. If you change to
-Algebraic Simplification mode, the result will be
-@samp{x + y + x => y + 2 x}. However, just pressing @kbd{a s}
-once will have no effect on @samp{x + y + x => x + y + x},
+formula @samp{arcsin(sin(x))} will not be handled by Calc's algebraic
+simplifications, but Calc's unsafe simplifications will reduce it to
+@samp{x}. If you enter @samp{arcsin(sin(x)) =>} normally, the result
+will be @samp{arcsin(sin(x)) => arcsin(sin(x))}. If you change to
+Extended Simplification mode, the result will be
+@samp{arcsin(sin(x)) => x}. However, just pressing @kbd{a e}
+once will have no effect on @samp{arcsin(sin(x)) => arcsin(sin(x))},
because the righthand side depends only on the lefthand side
and the current mode settings, and the lefthand side is not
-affected by commands like @kbd{a s}.
+affected by commands like @kbd{a e}.
The ``let'' command (@kbd{s l}) has an interesting interaction
with the @samp{=>} operator. The @kbd{s l} command evaluates the
other types of objects to be unordered, @code{beforep} puts any two
objects into a definite, consistent order. The @code{beforep}
function is used by the @kbd{V S} vector-sorting command, and also
-by @kbd{a s} to put the terms of a product into canonical order:
-This allows @samp{x y + y x} to be simplified easily to @samp{2 x y}.
+by Calc's algebraic simplifications to put the terms of a product into
+canonical order: This allows @samp{x y + y x} to be simplified easily to
+@samp{2 x y}.
@end defun
@defun equal x y
@end defun
@defun simplify expr
-Simplify the expression @var{expr} by applying various algebraic rules.
-This is what the @w{@kbd{a s}} (@code{calc-simplify}) command uses. This
-always returns a copy of the expression; the structure @var{expr} points
-to remains unchanged in memory.
+Simplify the expression @var{expr} by applying Calc's algebraic
+simplifications. This always returns a copy of the expression; the
+structure @var{expr} points to remains unchanged in memory.
More precisely, here is what @code{simplify} does: The expression is
first normalized and evaluated by calling @code{normalize}. If any
@c 7
@item
A prefix argument specifies simplification level and depth.
-1=Default, 2=like @kbd{a s}, 3=like @kbd{a e}.
+1=Basic simplifications, 2=Algebraic simplifications, 3=Extended simplifications
@c 8
@item