SET_SPEC_CONV : conv
STRUCTURE
SYNOPSIS
Axiom-scheme of specification for set abstractions.
LIBRARY
pred_set
DESCRIPTION
The conversion SET_SPEC_CONV expects its term argument to be an assertion of the form t IN {E | P}. Given such a term, the conversion returns a theorem that defines the condition under which this membership assertion holds. When E is just a variable v, the conversion returns:
   |- t IN {v | P} = P[t/v]
and when E is not a variable but some other expression, the theorem returned is:
   |- t IN {E | P} = ?x1...xn. (t = E) /\ P
where x1, ..., xn are the variables that occur free both in the expression E and in the proposition P.
EXAMPLE
- SET_SPEC_CONV ``12 IN {n | n > N}``;
|- 12 IN {n | n > N} = 12 > N

- SET_SPEC_CONV ``p IN {(n,m) | n < m}``;
|- p IN {(n,m) | n < m} = (?n m. (p = n,m) /\ n < m)
FAILURE
Fails if applied to a term that is not of the form t IN {E | P}.
HOL  Kananaskis-13