let K be Field; for p, q being FinSequence of holds len (mlt p,q) = min (len p),(len q)
let p, q be FinSequence of ; len (mlt p,q) = min (len p),(len q)
reconsider r = mlt p,q as FinSequence of ;
r = the multF of K .: p,q
by FVSUM_1:def 7;
hence
len (mlt p,q) = min (len p),(len q)
by FINSEQ_2:85; verum