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remprop Symbols Dictionary makunbound
Function

boundp

boundp symbol ⇒ generalized-boolean

Arguments and Values

symbola symbol.
generalized-booleana generalized boolean.

Description

Returns true if symbol is bound; otherwise, returns false.

Examples

 (setq x 1) ⇒  1
 (boundp 'x) ⇒  true
 (makunbound 'x) ⇒  X
 (boundp 'x) ⇒  false
 (let ((x 2)) (boundp 'x)) ⇒  false
 (let ((x 2)) (declare (special x)) (boundp 'x)) ⇒  true

Exceptional Situations

Should signal an error of type type-error if symbol is not a symbol.

See Also

set, setq, symbol-value, makunbound

Notes

The function bound determines only whether a symbol has a value in the global environment; any lexical bindings are ignored.

Backlinks

Constraints on the COMMON-LISP Package for Conforming Implementations, makunbound, symbol-value, symbol, Symbols as Forms, Symbols Dictionary, Symbols in the COMMON-LISP Package