# Type Specifier SATISFIES

Predicating.

### Compound Type Specifier Syntax

satisfies predicate-name

### Compound Type Specifier Arguments

predicate-name - a symbol.

### Compound Type Specifier Description

This denotes the set of all objects that satisfy the predicate predicate-name, which must be a symbol whose global function definition is a one-argument predicate. A name is required for predicate-name; lambda expressions are not allowed. For example, the type specifier `(and integer (satisfies evenp))` denotes the set of all even integers. The form `(typep x '(satisfies p))` is equivalent to `(if (p x) t nil)`.

The argument is required. The symbol * can be the argument, but it denotes itself (the symbol *), and does not represent an unspecified value.

The symbol satisfies is not valid as a type specifier.

\issue{TYPE-SPECIFIER-ABBREVIATION:X3J13-JUN90-GUESS}