theorem
  min(f,g) c= f\(f\g)
proof
  f\(f\g) = min(f,max(1_minus f,1_minus(1_minus g))) by FUZZY_1:11
    .= max(min(f,1_minus f),min(f,g)) by FUZZY_1:9;
  hence thesis by FUZZY_1:17;
end;
