(math-possible-signs): Added checks to intervals.

(math-pow-of-zero): Strengthen checks for positive and negative exponents.

diff --git a/lisp/calc/calc-arith.el b/lisp/calc/calc-arith.el
index a5c523240496c60b6e22f0198fd16481d97c9fd4..3a436cb1d36be8129b7e6b8cb49299c1134f48cc 100644 (file)
--- a/lisp/calc/calc-arith.el
+++ b/lisp/calc/calc-arith.el
@@ -387,9 +387,12 @@
               ((Math-negp a) 1)
               ((Math-zerop a) 2)
               ((eq (car a) 'intv)
-               (cond ((Math-zerop (nth 2 a)) 6)
-                     ((Math-zerop (nth 3 a)) 3)
-                     (t 7)))
+               (cond 
+                 ((math-known-posp (nth 2 a)) 4)
+                 ((math-known-negp (nth 3 a)) 1)
+                 ((Math-zerop (nth 2 a)) 6)
+                 ((Math-zerop (nth 3 a)) 3)
+                 (t 7)))
               ((eq (car a) 'sdev)
                (if (math-known-realp (nth 1 a)) 7 15))
               (t 8)))
@@ -1750,10 +1753,10 @@
         '(var nan var-nan)
       (math-reject-arg (list '^ a b) "*Indeterminate form")))
    ;; 0^positive = 0
-   ((math-posp b)
+   ((math-known-posp b)
     a)
    ;; 0^negative is undefined (let math-div handle it)
-   ((math-negp b)
+   ((math-known-negp b)
     (math-div 1 a))
    ;; 0^infinity is undefined
    ((math-infinitep b)