suspicious_recursion.m:031: Warning: recursive call to predicate
suspicious_recursion.m:031:   `funny_append'/3 is suspicious, because variables
suspicious_recursion.m:031:   whose names start with As and Bs occupy different
suspicious_recursion.m:031:   argument positions in the call than in the clause
suspicious_recursion.m:031:   head.
suspicious_recursion.m:031:   This warning can be disabled by wrapping the
suspicious_recursion.m:031:   recursive call inside a
suspicious_recursion.m:031:   `disable_warning [suspicious_recursion] (...)'
suspicious_recursion.m:031:   scope.
suspicious_recursion.m:042: Warning: recursive call to predicate `sum'/3 is
suspicious_recursion.m:042:   suspicious, because all input argument positions
suspicious_recursion.m:042:   that differ between the clause head and the call
suspicious_recursion.m:042:   use state variable notation.