This article develops elementary facts about a family of formal calculi described as '''propositional equation reasoning systems''' ('''PERS'''). This work follows on the ''alpha graphs'' that [[Charles Sanders Peirce]] devised as a graphical syntax for [[propositional calculus]] and also on the ''calculus of indications'' that George Spencer Brown presented in his ''Laws of Form''.<br clear="all">
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This article develops elementary facts about a family of formal calculi described as '''propositional equation reasoning systems''' ('''PERS'''). This work follows on the ''alpha graphs'' that [[Charles Sanders Peirce]] devised as a graphical syntax for [[propositional calculus]] and also on the ''calculus of indications'' that George Spencer Brown presented in his ''Laws of Form''.