let m, k be Nat; for R being Relation st iter ((iter (R,m)),k) = iter (R,(m * k)) holds
iter ((iter (R,m)),(k + 1)) = iter (R,(m * (k + 1)))
let R be Relation; ( iter ((iter (R,m)),k) = iter (R,(m * k)) implies iter ((iter (R,m)),(k + 1)) = iter (R,(m * (k + 1))) )
assume A1:
iter ((iter (R,m)),k) = iter (R,(m * k))
; iter ((iter (R,m)),(k + 1)) = iter (R,(m * (k + 1)))
thus iter ((iter (R,m)),(k + 1)) =
(iter (R,m)) * (iter ((iter (R,m)),k))
by Th68
.=
iter (R,((m * k) + (m * 1)))
by A1, Th76
.=
iter (R,(m * (k + 1)))
; verum