DEV Community

s
s

Posted on

1

Answer:

The notation you mention is not Haskell code, but a meta-notation for substitution which is frequently used in programming languages theory.

If e and t are Haskell expressions, and x is a Haskell variable, we write e [x := t] to denote the expression e where all the free occurrences…

Top comments (0)

Sentry image

See why 4M developers consider Sentry, “not bad.”

Fixing code doesn’t have to be the worst part of your day. Learn how Sentry can help.

Learn more