What are "reduction semantics"? Please explain the use of PLT Redex in layman's term

functional-programming, plt-redex, programming-languages, racket, semantics

Solution

Reduction semantics is a computation technique that involves replacing an expression by an equivalent (and hopefully smaller) expression until no more replacement is possible. If a language is Turing-complete, there are expressions that never stop replacing.

Reduction is usually notated by a right arrow, and it's best explained by example:

(3 + 7) + 5   -->  10 + 5  -->  15

This shows the standard reduction semantics for arithmetic expressions. The expression `15` cannot be reduced any further.

Hope this helps.

Problem

Original source