<Li> Functional programming languages support (and heavily use) first - class functions, anonymous functions and closures, although these concepts are being included in newer procedural languages . </Li> <Li> Functional programming languages tend to rely on tail call optimization and higher - order functions instead of imperative looping constructs . </Li> <P> Many functional languages, however, are in fact impurely functional and offer imperative / procedural constructs that allow the programmer to write programs in procedural style, or in a combination of both styles . It is common for input / output code in functional languages to be written in a procedural style . </P> <P> There do exist a few esoteric functional languages (like Unlambda) that eschew structured programming precepts for the sake of being difficult to program in (and therefore challenging). These languages are the exception to the common ground between procedural and functional languages . </P>

Discuss an approach to the development of procedure-oriented programs