
|     it is false that A
|
|     A and B
|
|     A or B
|
|     for every !a!, A
|
|     for some !a!, A
|
|     !b! in {!a! : A}
|
|     {!a! : A} in !b!
|
|     {!a! : A} in {!b! : B}
|
| Formulae are constructed recursively, beginning with
| the primitive formulae of (a) and proceeding via the
| constructions permitted by (b).
|
| II.  Classification Axiom-Scheme.
|
|      An axiom results if in the following &quot;!a!&quot; and &quot;!b!&quot;
|
|      are replaced by variables, &quot;A&quot; by a form