:: deftheorem APLikeDef defines AP-like NUMBER06:def 2 :
for f being real-valued Function holds
( f is AP-like iff for i, k being Nat st i in dom f & i + 1 in dom f & k in dom f & k + 1 in dom f holds
(f . (i + 1)) - (f . i) = (f . (k + 1)) - (f . k) );