theorem Th78:
 for E be Enumeration of {X} holds SignGenOp(f,B,{X}) * E= <* SignGen(f,B,X) *>
proof
  let E be Enumeration of {X};
A1: X in {X}=dom SignGenOp(f,B,{X}) & E = <*X*>
    by Th77,FUNCT_2:def 1,TARSKI:def 1;
  then SignGenOp(f,B,{X}) * E = <*SignGenOp(f,B,{X}).X*> by FINSEQ_2:34;
  hence thesis by A1,Def12;
end;
