defpred S₁[ Element of MSAAut U1, Element of MSAAut U1, set ] means $3 = $2 ** $1;
A1: for x, y being Element of MSAAut U1 ex m being Element of MSAAut U1 st S₁[x,y,m]

proof

let x, y be Element of MSAAut U1; :: thesis: ex m being Element of MSAAut U1 st S₁[x,y,m]
reconsider xx = x, yy = y as ManySortedFunction of U1,U1 ;
reconsider m = yy ** xx as Element of MSAAut U1 by Th26;
take m ; :: thesis: S₁[x,y,m]
thus S₁[x,y,m] ; :: thesis: verum

end;

thus ex IT being BinOp of (MSAAut U1) st
for x, y being Element of MSAAut U1 holds S₁[x,y,IT . (x,y)] from BINOP_1:sch 3(A1); :: thesis: verum