====<math>\varphi \land \psi \vdash \psi \land \varphi</math>====
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#====<math>(\varphi \land \psi) \land \delta \vdash \varphi \land (\psi \land \delta)</math>====<!--
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#<math>\varphi \vdash \varphi \land \varphi</math><!--