consider N being MonoidalSubStr of G;
H3( multLoopStr(# the carrier of N,the multF of N,the OneF of N #)) = H3(N) ;
then A1: for M being multLoopStr st G = M holds
H3( multLoopStr(# the carrier of N,the multF of N,the OneF of N #)) = H3(M) by Def24;
H2( multLoopStr(# the carrier of N,the multF of N,the OneF of N #)) c= H2(G) by Def24;
then multLoopStr(# the carrier of N,the multF of N,the OneF of N #) is MonoidalSubStr of G by A1, Def24;
hence ex b1 being MonoidalSubStr of G st b1 is strict ; :: thesis: verum