defpred S1[ Function, SortSymbol of , SortSymbol of ] means ( $2 = $3 & ex h being Endomorphism of A st $1 = h . $2 );
defpred S2[ SortSymbol of , set , set ] means ex s' being SortSymbol of ex f being Function of the Sorts of A . s',the Sorts of A . $1 ex x, y being Element of A,s' st
( S1[f,s',$1] & [x,y] in R . s' & $2 = f . x & $3 = f . y );
consider Q being ManySortedRelation of the Sorts of A such that
A5:
for s being SortSymbol of
for a, b being Element of A,s holds
( [a,b] in Q . s iff S2[s,a,b] )
from MSUALG_6:sch 2();
reconsider Q = Q as ManySortedRelation of A ;
reconsider Q = Q as stable ManySortedRelation of A by A5, Lm2;
take
Q
; ( R c= Q & ( for Q being stable ManySortedRelation of A st R c= Q holds
Q c= Q ) )
thus
( R c= Q & ( for Q being stable ManySortedRelation of A st R c= Q holds
Q c= Q ) )
by A5, Lm2; verum