\DOC RENAME_VARS_CONV
\TYPE {Conv.RENAME_VARS_CONV : string list -> term -> thm}
\SYNOPSIS
Renames variables underneath a binder.
\KEYWORDS
Alpha-conversion.
\LIBRARY
Conv
\DESCRIBE
{RENAME_VARS_CONV} takes a list of strings specifying new names for variables under a binder. More precisely, it will rename variables in abstractions, or bound by universal, existential, unique existence or the select (or Hilbert-choice) ``quantifier''.
More than one variable can be renamed at once. If variables occur past the first, then the renaming continues on the appropriate sub-term of the first. (That is, if the term is an abstraction, then renaming will continue on the body of the abstraction. If it is one of the supported quantifiers, then renaming will continue on the body of the abstraction that is the argument of the ``binder constant''.)
If {RENAME_VARS_CONV} is passed the empty list, it is equivalent to
{ALL_CONV}. The binders do not need to be of the same type all the way into the term.
\FAILURE
Fails if an attempt is made to rename a variable in a term that is not an abstraction, or is not one of the accepted quantifiers. Also fails if all of the names in the list are not distinct.
\EXAMPLE
{
- RENAME_VARS_CONV ["a", "b"] ``\x y. x /\ y``;
> val it = |- (\x y. x /\ y) = (\a b. a /\ b) : thm
- RENAME_VARS_CONV ["a", "b"] ``!x:'a y. P x /\ P y``;
> val it = |- (!x y. P x /\ P y) = !a b. P a /\ P b : thm
- RENAME_VARS_CONV ["a", "b"] ``!x:'a. ?y. P x /\ P y``;
> val it = |- (!x. ?y. P x /\ P y) = !a. ?b. P a /\ P b : thm
}
\USES
Post-processing mangling of names in code implementing derived logical procedures to make names look more appropriate. Changing names can only affect the presentation of terms, not their semantics.
\SEEALSO
Term.aconv, Thm.ALPHA, SWAP_VARS_CONV.
\ENDDOC