Error, (in assume) cannot assume on a constant object - Maple Programming Help

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Error, (in assume) cannot assume on a constant object

Error, (in assume) cannot assume on an assigned name

 

Description

Examples

Description

The assume command sets variable properties and relationships between variables. A common use of the assume command is assume(a>0). This states that the symbol a is assumed to be a positive real constant. Having made such an assumption, Maple routines are able to use this information to simplify expressions, for example, a2bto ab, and evaluate inequalities, for example, is(a+1>0) returns true.

 

The cannot assume on a constant object error occurs when the expression on which to place the assumption does not contain a name on which to base the assumption, for example, a variable that has been assigned a constant value.

Examples

Example 1:

xπ;

xπ

(2.1)

assumex>0;

Error, (in assume) cannot assume on a constant object

The variable x is replaced by the value assigned to that variable.

 

Solution: Use unevaluation quotes to prevent the variable from being replaced by its value.

assumex>0;

Note that this removes the previously assigned value.

x;

x~

(2.2)

Example 2:

Similarly, an assigned name could be a Maple name, which is protected.

assumeroot>0;

Error, (in assume) cannot assume on an assigned name

root3;

Error, attempting to assign to `root` which is protected.  Try declaring `local root`; see ?protect for details.

 

Solution: Use a different name.

See Also

assume

protect

type/constant