Rule of Assumption/Proof Rule

Proof Rule
The rule of assumption is a valid deduction sequent in propositional logic.

As a proof rule it is expressed in the form:


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

Also known as
Some sources refer to this as the rule of assertion.

Also see

 * Definition:Premise
 * Law of Identity

Technical Note
When invoking the Rule of Assumption in a tableau proof, use the Assumption template:



or:

where:
 * is the number of the line on the tableau proof where the assumption is to be invoked
 * is the statement of logic that is to be displayed in the Formula column, without the  delimiters
 * is the (optional) comment that is to be displayed in the Notes column.

When the assumption being made is a premise, use the Premise template::



or:

in the same manner as above.