EXISTS_CONSEQ_CONVConseqConv.EXISTS_CONSEQ_CONV : (conseq_conv -> conseq_conv)
Applies a consequence conversion to the body of an existentially quantified term.
If c is a consequence conversion that maps a term
``t x`` to a theorem |- t x = t' x,
|- t' x ==> t x or |- t x ==> t' x, then
EXISTS_CONSEQ_CONV c maps ``?x. t x`` to
|- ?x. t x = ?x. t' x,
|- ?x. t' x ==> ?x. t x or
|- ?x. t x ==> ?x. t' x, respectively.
EXISTS_CONSEQ_CONV c t fails, if t is not
an existentially quantified term or if c fails on the body
of t.
Conv.QUANT_CONV, ConseqConv.FORALL_CONSEQ_CONV,
ConseqConv.QUANT_CONSEQ_CONV