CoCoA:IsDefined

IsDefined

check if an expression has been defined

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
-------------------------------

Syntax

IsDefined(E)

where E is a CoCoA expression.

   <type>memory</type>
   <type>boolean</type>