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With::lvw

Details

  • This message is generated when the first element in With is not a list of assignments to symbols.
  • You can use Block or Module to introduce local variables without assigning values to those variables.
  • Current versions of the Wolfram Language do not support local variables that are not symbols.
  • Off[message] switches off the message; On[message] switches it on. For example: Off[With::lvw].

Examples

Basic Examples  (2)

This input generates a message because the first element in With is not a list of assignments to symbols. The expression x[0] is a normal expression rather than a symbol:

Wolfram Language code: With[{x[0]}, x[0] = 2;1 + x[0]]

Correct use of With requires a list of assignments to symbols:

Wolfram Language code: With[{x0 = 2}, 1 + x0]

This message will also be generated if the first element in With is a list of strings:

Wolfram Language code: With[{"package"}, 2 + 2]