**15**

Functional Programming Languages

**function**: a mathematical correspondence that assigns exactly one element of one set to each element of the same or another set

*Webster’s Dictionary*

The mathematical notion of function is that if *f* (*x*) = *a* “this time,” then *f* (*x*) = *a* “next time”; there is no other value equal to *f* (*x*). This allows the use of *equational reasoning* familiar from algebra: that if *a* = *f* (*x*) then *g* (*f* (*x*), *f* (*x* )) is equivalent to *g* (*a* , *a*). *Pure functional* programming languages encourage a kind of programming in which equational reasoning ...

Start Free Trial

No credit card required