let G be non empty multMagma ; for M being MonoidalExtension of G holds
( the carrier of M = the carrier of G & the multF of M = the multF of G & ( for a, b being Element of M
for a9, b9 being Element of G st a = a9 & b = b9 holds
a * b = a9 * b9 ) )
let M be MonoidalExtension of G; ( the carrier of M = the carrier of G & the multF of M = the multF of G & ( for a, b being Element of M
for a9, b9 being Element of G st a = a9 & b = b9 holds
a * b = a9 * b9 ) )
A1:
multMagma(# the carrier of M, the multF of M #) = multMagma(# the carrier of G, the multF of G #)
by Def22;
hence
( H1(M) = H1(G) & H2(M) = H2(G) )
; for a, b being Element of M
for a9, b9 being Element of G st a = a9 & b = b9 holds
a * b = a9 * b9
let a, b be Element of M; for a9, b9 being Element of G st a = a9 & b = b9 holds
a * b = a9 * b9
let a9, b9 be Element of G; ( a = a9 & b = b9 implies a * b = a9 * b9 )
thus
( a = a9 & b = b9 implies a * b = a9 * b9 )
by A1; verum