to second :thing
op first bf :thing
end

to twice :thing
pr :thing
pr :thing
end

to pigl :word
if vowelp first :word [op word :word "ay]
op pigl word bf :word first :word
end

to vowelp :let
op memberp :let "aeiou
end

to piglatin :sent
if emptyp :sent [op []]
op fput pigl first :sent piglatin bf :sent
end

to factorial :n
if :n=0 [output 1]
output :n * factorial :n-1
end

to memberp :thing :list
if emptyp :list [op "false]
if equalp :thing first :list [op "true]
op memberp :thing bf :list
end

to repeat :num :instr
if :num=0 [stop]
run :instr
repeat :num-1 :instr
end