set S = 1GateCircStr p,f;
let A1, A2 be strict non-empty MSAlgebra of 1GateCircStr p,f; ( the Sorts of A1 = the carrier of (1GateCircStr p,f) --> X & the Charact of A1 . [p,f] = f & the Sorts of A2 = the carrier of (1GateCircStr p,f) --> X & the Charact of A2 . [p,f] = f implies A1 = A2 )
assume A14:
( the Sorts of A1 = the carrier of (1GateCircStr p,f) --> X & the Charact of A1 . [p,f] = f & the Sorts of A2 = the carrier of (1GateCircStr p,f) --> X & the Charact of A2 . [p,f] = f & not A1 = A2 )
; contradiction
A15:
the carrier' of (1GateCircStr p,f) = {[p,f]}
by Def6;
then
dom the Charact of A1 = {[p,f]}
by PARTFUN1:def 4;
then A16:
the Charact of A1 = {[[p,f],f]}
by A14, GRFUNC_1:18;
dom the Charact of A2 = {[p,f]}
by A15, PARTFUN1:def 4;
hence
contradiction
by A14, A16, GRFUNC_1:18; verum