A function concept that allows for intensionally equivalent functions to be distinct is called hyperintensional. The point is that in possible-worlds terminology, the function concept at work in the \(\lambda\)-calculus may be regarded not as intentional but hyperintensional—in contrast to what the terminology common in the foundations of mathematics says. Note that it’s unclear how an intensional semantic framework, like the possible-worlds framework, could even in principle account for a non-intensional function concept. On the semantics of the \(\lambda\)-calculus, see section 7. The point here was simply to clarify any conceptual confusions that might arise from different terminologies at play in philosophical discourse.