Noninterchangeable and Nonequivalent

Noninterchangeable adjective - Such that the terms of an expression cannot be interchanged without changing the meaning.

Nonequivalent and noninterchangeable are semantically related. In some cases you can use "Nonequivalent" instead an adjective "Noninterchangeable".

Nonequivalent adjective - Not equal or interchangeable in value, quantity, or significance.

Noninterchangeable and nonequivalent are semantically related. You can use "Noninterchangeable" instead an adjective "Nonequivalent".