(math-integrate-by-parts): Removed unused variable var-thing.

(math-integrate-by-parts):  Removed unused variable var-thing.

(math-integ-depth, math-integ-level, math-integral-limit)
(math-enable-subst, math-any-substs, math-integ-msg)
(math-prev-parts-v, math-good-parts, math-max-integral-limit)
(math-int-threshold, math-int-factors, math-double-roots)
(math-solve-simplifying, var-IntegLimit, math-solve-sign)
(var-GenCount):  Declared these variables.
(calcFunc-integ):  Don't check if var-IntegLimit is bound.

(math-integral-cache, math-integral-cache-state):  Move declarations
to earlier in the file.

(math-deriv-var, math-deriv-total, math-deriv-symb):  New variables.
(math-derivative, calcFunc-deriv, calcFunc-tderiv):  Replace
variables deriv-var, deriv-total and deriv-symb by declared variables
math-deriv-var, math-deriv-total and math-deriv-symb.

(math-cur-record):  New variable.
(math-integral, math-replace-integral-parts, math-integrate-by-parts)
(calc-dump-integral-cache, math-try-integral):  Replace variable
cur-record by declared variable math-cur-record.

(math-has-rules):  New variable.
(math-try-integral, math-do-integral):  Use declared variable
math-has-rules instead of has-rules.

(math-t1, math-t2, math-t3):  New variables.
(math-do-integral, math-do-integral-methods, math-try-solve-for)
(math-try-solve-prod, math-solve-poly-funny-powers)
(math-solve-crunch-poly, math-decompose-poly)
(math-solve-find-root-term, math-find-root-in-prod):  Replace
variables t1, t2, t3 by declared variables math-t1, math-t2,
math-t3.

(math-so-far, math-integ-expr):  New variables.
(math-do-integral-methods, math-integ-try-linear-substitutions)
(math-integ-try-substitutions):  Replace variables so-far and expr by
declared variables math-so-far and math-integ-expr.

(math-expr-parts):  New variable.
(math-expr-rational-in, math-expr-rational-in-rec):  Replace variable
parts by declared variable math-expr-parts.

(calc-low, calc-high):  New variables.
(calcFunc-table, math-scan-for-limits):  Replaced variable low and
high with the declared variable calc-low and calc-high.

(math-solve-var, math-solve-full):  New variables.
(math-try-solve-for, math-try-solve-prod, math-solve-prod)
(math-decompose-poly, math-solve-quartic, math-poly-all-roots)
(math-solve-find-root-in-prod, math-solve-for, math-solve-system)
(math-solve-system-rec, math-solve-get-sign, math-solve-get-int):
Replace variables solve-var and solve-full with declared variables
math-solve-var and math-solve-full.

(math-solve-vars):  New variable.
(math-solve-system, math-solve-system-rec):  Replace variable
solve-vars with declared variable math-solve-vars.

(math-try-solve-sign):  New variable.
(math-try-solve-for, math-try-solve-prod):  Replace variable
sign by declared variable math-try-solve-sign.

(math-solve-b):  New variable.
(math-solve-poly-funny-powers, math-decompose-poly):  Replace variable
b by declared variable math-solve-b.

(math-solve-system-vv, math-solve-res):  New variables
(math-solve-system-rec, math-solve-system-subst):  Replaced variables
vv and res with declared variables math-solve-system-vv and
math-solve-system-res.