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IsDefined

check if an expression has been defined

Syntax

IsDefined(E) where E is a CoCoA expression.

Description

This function returns TRUE if E is defined, otherwise it returns false. Typically, it is used to check if a name has already been assigned.

NOTE: this function used to be named Defined.

Example

IsDefined(MyVariable); FALSE ------------------------------- MyVariable := 3; IsDefined(MyVariable); TRUE -------------------------------