let p1, p2 be set ; :: thesis: p1 .. <*p1,p2*> = 1
A1: for i being Nat st 1 <= i & i < 1 holds
<*p1,p2*> . i <> <*p1,p2*> . 1 ;
len <*p1,p2*> = 2 by FINSEQ_1:44;
then A2: 1 in dom <*p1,p2*> by FINSEQ_3:25;
<*p1,p2*> . 1 = p1 by FINSEQ_1:44;
hence p1 .. <*p1,p2*> = 1 by A2, A1, Th2; :: thesis: verum