theorem Problem64Part1: :: NUMBER06:41
for k, l, m being Nat st 0 < k & k < l & l < m & ( not k = 2 or not l = 3 or not m = 4 ) & ( not k = 1 or not l = 4 or not m = 5 ) & (Fib m) - (Fib l) = (Fib l) - (Fib k) & (Fib l) - (Fib k) > 0 holds
( l > 2 & k = l - 2 & m = l + 1 )