There's an added complication that `a(b, c)` could mean "call `a` with two arguments `b` and `c`" or it could mean "call `,` with two arguments `b` and `c` to f

There's an added complication that `a(b, c)` could mean "call `a` with two arguments `b` and `c`" or it could mean "call `,` with two arguments `b` and `c` to form the pair `(b,c)`, then call `a` with that one argument". The latter would be written `a([b, c])` in other languages. These are all isomorphic (we're calling `a` and giving access to `b` and `c`), but can confuse people who are new to the syntax.