Boolean Ring

$\textbf{BooleanRing} \; A \; \otimes \; \oplus \; I \; U$

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$\textbf{UnitRing} \; A \; \otimes \; \oplus \; I \; U$

$\textbf{Idempotent} \; A \; \otimes$

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pred BooleanRing(A: set univ, tms,pls: univ->univ->univ, I,U: univ) {
  UnitRing[A,tms,pls,I,U]
  Idempotent[A,tms]
}