Syntax Definition wbr 4426

Description: Extend wff notation to include the general binary relation predicate. Note that the syntax is simply three class symbols in a row. Since binary relations are the only possible wff expressions consisting of three class expressions in a row, the syntax is unambiguous. (For an example of how syntax could become ambiguous if we are not careful, see the comment in cneg 9860.)

Hypotheses

Ref	Expression
cA	class A
cB	class B
cR	class R

Assertion

Ref	Expression
wbr	wff A R B

See definition df-br 4427 for more information.