jit.expr: missing siblings converting infix to prefix (*)

I wish to map jit.noise (0.0-1.0 range) onto, say, -0.05 to 0.05.

I could do it with two jit.op's but this will get old very fast, because this is a common operation.

I thought it would be easier with [jit.expr @expr in[0] * 0.1 - 0.05] but I get the error "jit.expr: missing siblings converting infix to prefix (*)."

What am I missing?

hjh