subst_occs : int list list -> (term,term) subst -> term -> term
STRUCTURE
HolKernel
SYNOPSIS
Substitutes for particular occurrences of subterms of a given term.
DESCRIPTION
For each {redex,residue} in the second argument, there should be a corresponding integer list l_i in the first argument that specifies which free occurrences of redex_i in the third argument should be substituted by residue_i.
FAILURE
Failure occurs if any substitution fails, or if the length of the first argument is not equal to the length of the substitution. In other words, every substitution pair should be accompanied by a list specifying when the substitution is applicable.
EXAMPLE
- subst_occs [[1,3]] [Term `SUC 0` |-> Term `1`]
             (Term `SUC 0 + SUC 0 = SUC(SUC 0)`);
> val it = `1 + SUC 0 = SUC 1` : term

- subst_occs [[1],[1]] [Term `SUC 0` |-> Term `1`,
                        Term `SUC 1` |-> Term `2`]
             (Term `SUC(SUC 0) = SUC 1`);
> val it = `SUC 1 = 2` : term

- subst_occs [[1],[1]] [Term`SUC(SUC 0)` |-> Term `2`,
                        Term`SUC 0`      |-> Term `1`]
             (Term`SUC(SUC 0) = SUC 0`);
> val it = `2 = 1` : term

SEEALSO
subst, |->
HOL  Kananaskis-13