Thun/docs/reference/cond.md

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# cond
Basis Function Combinator
This combinator works like a case statement. It expects a single quote
on the stack that must contain zero or more condition quotes and a
default quote. Each condition clause should contain a quoted predicate
followed by the function expression to run if that predicate returns
true. If no predicates return true the default function runs.
It works by rewriting into a chain of nested [ifte]{.title-ref}
expressions, e.g.:
[[[B0] T0] [[B1] T1] [D]] cond
-----------------------------------------
[B0] [T0] [[B1] [T1] [D] ifte] ifte
Gentzen diagram.
## Definition
if not basis.
## Derivation
if not basis.
## Source
if basis
## Discussion
## Crosslinks