let seq1, seq2 be sequence of X; ( ( for n being Nat holds seq1 . n = (Rseq . n) * (seq . n) ) & ( for n being Nat holds seq2 . n = (Rseq . n) * (seq . n) ) implies seq1 = seq2 )
assume that
A2:
for n being Nat holds seq1 . n = (Rseq . n) * (seq . n)
and
A3:
for n being Nat holds seq2 . n = (Rseq . n) * (seq . n)
; seq1 = seq2
let n be Element of NAT ; FUNCT_2:def 8 K64(seq1,n) = K64(seq2,n)
seq1 . n = (Rseq . n) * (seq . n)
by A2;
hence
seq1 . n = seq2 . n
by A3; verum