This error occurs when you execute an expression that cannot be understood by Maple.  The error occurs with 2-D math that cannot be parsed.  Ensure you use valid Maple syntax.  Use the help system to find the valid Maple syntax for the operation you want to perform.  The best ways to construct expressions in 2-D math are to use the Expression palette or the command completion templates.

Sometimes, you want to show an expression in mathematical notation that is not valid Maple syntax. If such an expression is executed accidentally, it can lead to error messages. If this happens, toggling the expression to nonexecutable math removes the error message and changes the math to nonexecutable. To change an expression to nonexecutable math use the shortcut key Shift + F5.  For more information, see Executable and Nonexecutable Math or see example 2 below.

Example 1

This error occurred because the expression is not complete.

Solution:

Example 2 - Error appears for math in a paragraph or formula

Use the

This error occurred because the expression is not valid Maple syntax.

Solution 1:  Change the expression to nonexecutable math: click the expression, and use the shortcut key Shift + F5.  The error message is removed. For more information, see Executable and Nonexecutable Math.

Use the ⊥ symbol to indicate that two lines are perpendicular.

Solution 2:  Select the expression, then from the Format menu select Convert To>Atomic Variable.  This turns the expression from a mathematical object to a single name.  Maple no longer tries to parse the expression.  Now, when it is executed there is no parse error.

Use the $\perp$ symbol to indicate that two lines are perpendicular.