consider f being Element of FuncsT X, T1, T2 being Element of TOL X such that
A1: m = [[T1,T2],f] and
( T2 `2 = {} implies T1 `2 = {} ) and
f is Function of (T1 `2),(T2 `2) and
for x, y being set st [x,y] in T1 `1 holds
[(f . x),(f . y)] in T2 `1 by Th41;
[T1,T2] = m `1 by A1, MCART_1:def 1;
hence (m `1) `1 is Element of TOL X by MCART_1:def 1; :: thesis: verum