BQN uses the 2-modifiers ⊸⟜ for hooks and, because data values (numbers, characters, and arrays) apply as constant functions, to bind arguments to functions. I

BQN uses the 2-modifiers ⊸⟜ for hooks and, because data values (numbers, characters, and arrays) apply as constant functions, to bind arguments to functions. I find them very flexible and intuitive and would say they're one of its best features. For example, F⊸G⟜H is the function that applies F to its left argument, H to its right, and then G to the results together. As in Dyalog APL (and subsequently NARS2000, ngn/apl, and dzaima/APL), BQN uses the two-train for simple composition, so that (F G) applies F to the result of G. The "nothing" indicator · allows a function's left argument to be omitted and can accomplist the same thing: (·F G) is another way to write that 2-train, and can be part of a longer train with more functions to the left. So it functions like J's Cap, but also works outside of trains.