This message is generated when the argument in NumericQ on the left side of an assignment is not a symbol, or the expression on the right side is not True or False.
Off[message] switches off the message; On[message] switches it on. For example: Off[NumericQ::set].
Examples
Basic Examples(1)
An error occurs because the right side of this assignment is not True or False:
These inputs set a numerical value for the test symbol and specify that the test symbol is a numeric quantity:
The test symbol now has a numerical value and will be treated as a numeric quantity:
