let x1, x2 be set ; for X being non empty finite set
for f being Function of (2 -tuples_on X),X
for S being Signature of X st x1 in the carrier of S & x2 in the carrier of S & not Output (1GateCircStr <*x1,x2*>,f) in InputVertices S holds
InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S
let X be non empty finite set ; for f being Function of (2 -tuples_on X),X
for S being Signature of X st x1 in the carrier of S & x2 in the carrier of S & not Output (1GateCircStr <*x1,x2*>,f) in InputVertices S holds
InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S
let f be Function of (2 -tuples_on X),X; for S being Signature of X st x1 in the carrier of S & x2 in the carrier of S & not Output (1GateCircStr <*x1,x2*>,f) in InputVertices S holds
InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S
A1:
rng <*x1,x2*> = {x1,x2}
by FINSEQ_2:147;
let S be Signature of X; ( x1 in the carrier of S & x2 in the carrier of S & not Output (1GateCircStr <*x1,x2*>,f) in InputVertices S implies InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S )
assume
( x1 in the carrier of S & x2 in the carrier of S )
; ( Output (1GateCircStr <*x1,x2*>,f) in InputVertices S or InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S )
then
rng <*x1,x2*> c= the carrier of S
by A1, ZFMISC_1:38;
hence
( Output (1GateCircStr <*x1,x2*>,f) in InputVertices S or InputVertices (S +* (1GateCircStr <*x1,x2*>,f)) = InputVertices S )
by Th39; verum