Factorial in FP

Example for versions Furry Paws

This example works in exactly the same way as the one in Interactive FP, except for that it doesn’t define zero function, since it’s built-in. Note that here all operations are done within integer data type, and 13! overflows it, so the program can be called only to print factorials up to 12!. show is another way to output data. 

dec = sub.[id, ~1]
seq = zero -> [id] ; cat.[seq.dec, [id]]
factorial = zero -> ~1 ; mul.[id, factorial.dec]

main = show.(return @factorial.(seq.~12))