samth/var — Issue #2: Parallel subst is TOTALLY broken
Author: dvanhorn
Created: 2011-10-12 20:26:07+00:00
State: open

parallel subst (subst*) is broken. It does one at a time substitution which causes problems if a substituted in expression refers to a variable to be substituted, eg.

(subst* (f g) (g 7) f) => 7, but should be g.

If all substituted expressions were closed, this wouldn't arise, but since terms may be open wrt module references, this breaks when module references and bound variables overlap.