For readability and convenience, infix notation such as x * y is recognized and translated to Block-Diagram Normal Form (BDNF) as x,y:*, i.e., the parallel signals x and y are fed to the two-input multiplier *. Similarly, the notation f(x) is rewritten to x:f if f is a primitive function. (More generally, f(x) is first rewritten as possible using pattern-matching (§2.23) and definition-expansion (§2.7)). Postfix operators such as ' are handled similarly. More formally, we can write
and so on.