\def-lazy(_if1_ 2 $0)\ \def-lazy(_if0_ 2 $1)\ \def-lazy(if 3 \({_if$0_} $1 $2))\ \if(0 a {b\(if 1 c d)}) \def(x 1 \(if $0 0 1))\ \if(\x(1) y z)