Syntax Definition cab 2151

Description: Introduce the class builder or class abstraction notation ("the class of sets x such that ph is true"). Our class variables A, B, etc. range over class builders (sometimes implicitly). Note that a setvar variable can be expressed as a class builder per Theorem cvjust 2160, justifying the assignment of setvar variables to class variables via the use of cv 1342.

Hypotheses

Ref	Expression
wph	wff ph
vx	setvar x

Assertion

Ref	Expression
cab	class { x | ph }

See definition df-clab 2152 for more information.