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citation

The rule name and line numbers written beside a proof line to justify it.

Every line of a formal proof carries a citation: PR for a premise, AS for an assumption, or a rule name followed by the numbers of the lines or subproofs the rule is applied to.

Examples

  • "→E 1, 2" cites conditional elimination applied to lines 1 and 2.

See also

rule of inference formal proof
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