[Power Query] Closures, partial application and cascading parameters

closureExample.ts

let
   addTo = (x) => (y) => x + y,
//make a closure with scope x=5
   addToFive = addTo(5),
//becomes addTo(5) => (y) => 5 + y
   eight = addToFive(3)
in //becomes addTo(5) => (3) => 5 + 3
   eight