Rule of Assumption/Proof Rule/Tableau Form

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Proof Rule

Let $\phi$ be a propositional formula.

The Rule of Assumption is invoked for $\phi$ in a tableau proof in the following manner:

Pool:    The line on which the Rule of Assumption is invoked      
Formula:    $\phi$      
Description:    Assumption or Premise      
Depends on:    (None)      
Abbreviation:    $\mathrm A$ or $\mathrm P$ accordingly      

Note that the Description: field of the Rule of Assumption is populated with either:

$(1): \quad$ Premise if the statement being assumed is one of the premises of the argument


$(2): \quad$ Assumption if it is to be discharged later in the proof.

On completion of the proof, only those lines annotated Premise are to remain in the pool of assumptions of the conclusion.

Also defined as

Some sources introduce the formula line as:

Show $\phi$