PROC test(a=10,b=20,c=30) PrintF('a=\d,b=\d,c=\d\n',a,b,c) ENDPROC
test(,,40) test() test(,,) // this is the same as the above one test(1,2,3) test(,123)
[1,0,2,0,3]
[1,,2,,3]