I tried it and it ran, so it seems to be syntactically correct. I suspect that you knew that, and were wondering about a slightly deeper problem.

Since I've no clue as to what level of wrongness you're concerned with, I am left to wonder why why would you want to do it that way, vs using array syntax?. This would save having to have code such as

$a494141 = exp(( 4.0*atan(1.0) * sqrt(-1)));
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