In Haskell such identifiers can be used as infix operators (as we will see below). Otherwise (.) is defined as any other function. Please also note how close the syntax is to the original mathematical definition
Syntax analysis-inverse Polish algorithm The reverse Polish algorithm forms a stack (ie reverse Polish expression) in the grammatical analysis stage. The core of this expression is to convert the infix expression that we usually use to a postfix expression. The parentheses only indicate the order o...