let j, i be Element of NAT ; for K being non empty multMagma
for a1, a2 being Element of K
for R1, R2 being Element of i -tuples_on the carrier of K st j in Seg i & a1 = R1 . j & a2 = R2 . j holds
(mlt R1,R2) . j = a1 * a2
let K be non empty multMagma ; for a1, a2 being Element of K
for R1, R2 being Element of i -tuples_on the carrier of K st j in Seg i & a1 = R1 . j & a2 = R2 . j holds
(mlt R1,R2) . j = a1 * a2
let a1, a2 be Element of K; for R1, R2 being Element of i -tuples_on the carrier of K st j in Seg i & a1 = R1 . j & a2 = R2 . j holds
(mlt R1,R2) . j = a1 * a2
let R1, R2 be Element of i -tuples_on the carrier of K; ( j in Seg i & a1 = R1 . j & a2 = R2 . j implies (mlt R1,R2) . j = a1 * a2 )
assume
j in Seg i
; ( not a1 = R1 . j or not a2 = R2 . j or (mlt R1,R2) . j = a1 * a2 )
then
j in Seg (len (mlt R1,R2))
by FINSEQ_1:def 18;
then
j in dom (mlt R1,R2)
by FINSEQ_1:def 3;
hence
( not a1 = R1 . j or not a2 = R2 . j or (mlt R1,R2) . j = a1 * a2 )
by FUNCOP_1:28; verum