SUBST.html -- ACL2 Version 6.3

### SUBST

a single substitution into a tree

    Major Section:  ACL2-BUILT-INS

`(Subst new old tree)` is obtained by substituting `new` for every occurence of `old` in the given tree.

Equality to `old` is determined using the function `eql`. The guard for `(subst new old tree)` requires `(eqlablep old)`, which ensures that the guard for `eql` will be met for each comparison generated by `subst`.

`Subst` is defined in Common Lisp. See any Common Lisp documentation for more information.

To see the ACL2 definition of this function, see pf.