Rule of Assumption/Proof Rule

Proof Rule
The rule of assumption is a valid argument in many proof systems, including natural deduction.

As a proof rule it is expressed in the form:


 * An assumption $\phi$ may be introduced at any stage of an argument.

Also see

 * This is a rule of inference of the following proof system:
 * Definition:Natural Deduction


 * Definition:Premise
 * Law of Identity