let V be SetValuation; for P being Permutation of V
for p, q being Element of HP-WFF st Perm (P,q) is with_fixpoint holds
Perm (P,(p => q)) is with_fixpoint
let P be Permutation of V; for p, q being Element of HP-WFF st Perm (P,q) is with_fixpoint holds
Perm (P,(p => q)) is with_fixpoint
let p, q be Element of HP-WFF ; ( Perm (P,q) is with_fixpoint implies Perm (P,(p => q)) is with_fixpoint )
given x being object such that A1:
x is_a_fixpoint_of Perm (P,q)
; ABIAN:def 5 Perm (P,(p => q)) is with_fixpoint
reconsider xx = x as set by TARSKI:1;
take
(SetVal (V,p)) --> xx
; ABIAN:def 5 (SetVal (V,p)) --> xx is_a_fixpoint_of Perm (P,(p => q))
thus
(SetVal (V,p)) --> xx is_a_fixpoint_of Perm (P,(p => q))
by A1, Th14; verum