consider f being sequence of NAT such that
A1:
( f . 0 = m div n & f . 1 = n div (m mod n) )
and
A2:
for n being Nat holds f . (n + 2) = H1(n,f . n,f . (n + 1))
from RECDEF_2:sch 5();
reconsider f = f as sequence of NAT ;
take
f
; ( f . 0 = m div n & f . 1 = n div (m mod n) & ( for k being Nat holds f . (k + 2) = ((modSeq (m,n)) . k) div ((modSeq (m,n)) . (k + 1)) ) )
thus
( f . 0 = m div n & f . 1 = n div (m mod n) )
by A1; for k being Nat holds f . (k + 2) = ((modSeq (m,n)) . k) div ((modSeq (m,n)) . (k + 1))
let k be Nat; f . (k + 2) = ((modSeq (m,n)) . k) div ((modSeq (m,n)) . (k + 1))
thus
f . (k + 2) = ((modSeq (m,n)) . k) div ((modSeq (m,n)) . (k + 1))
by A2; verum