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subst_assoc                                                      (Lib)
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subst_assoc : ('a -> bool) -> ('a,'b)subst -> 'b option

SYNOPSIS
Treats a substitution as an association list.

KEYWORDS
Substitution, association list.

DESCRIBE
An application {subst_assoc P [{redex_1,residue_1},...,{redex_n,residue_n}]}
returns {SOME residue_i} if {P} holds of {redex_i}, and did not hold
(or fail) for {{redex_j | 1 <= j < i}}.  If {P} holds for none of
the {redex}es in the substitution, {NONE} is returned.

FAILURE
If {P redex_i} fails for some {redex} encountered in the left-to-right
traversal of the substitution.

EXAMPLE

- subst_assoc is_abs [T |-> F, Term `\x.x` |-> Term `combin$I`];
> val it = SOME`I` : term option




SEEALSO
Lib.assoc, Lib.rev_assoc, Lib.assoc1, Lib.assoc2, Lib.|->.

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