Go / sleep

Anyone working with sapf playing around with go / sleep ? and have a very simple example you can share… this plays the fist square but not the sine in the function.

\[
	[110 55] .5 1 steps 0 square .1 * 
 	\[1 sleep [330 550] .2 1 steps 0 sinosc .1 *] go
] ! play

this works

\[
	"this" pr cr
	\[1 sleep "that" pr cr ] go

] ! 

sorry for the Im sure very simple question