[Maxima] Incompatible changes .. was Re: Program stack overflow defining infix operator

[Barton Willis]

Maxima already has simplifying and non-simplifying logical connectives.
Both conjunctions are named "and." The simplifying and noncommutative "and"

(%i6) a and b;
  1> (SIMP-MAND ((MAND) $A $B) 1 NIL)
  <1 (SIMP-MAND ((MAND SIMP) $A $B))
(%o6) a and b

And the nonsimplifying "and"

(%i7) if a and b then 42 else 0;
  1> (IS-MAND ($A $B))
  <1 (IS-MAND ((MAND) $A $B))
  1> (SIMP-MAND ((MAND) $A $B) 1 NIL)
  <1 (SIMP-MAND ((MAND SIMP) $A $B))
(%o7) if a and b then 42 else 0

This conjunction gets routed through is-mand and simp-mand.
Further there is a defmspec mand function. The function mand
is sometimes called before simp-mand

(%i14) a and b;
1 Enter "and" [a and b]
1 Exit  "and" a and b
  1> (SIMP-MAND ((MAND) $A $B) 1 NIL)
  <1 (SIMP-MAND ((MAND SIMP) $A $B))
(%o14) a and b


Barton