Cartesian monoid

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A Cartesian monoid is a monoid, with additional structure of pairing and projection operators. It was first formulated by Dana Scott and Joachim Lambek independently. [1]

Definition

A Cartesian monoid is a structure with signature where and are binary operations, , and are constants satisfying the following axioms for all in its universe:

Monoid
is a monoid with identity
Left Projection
Right Projection
Surjective Pairing
Right Homogeneity

The interpretation is that and are left and right projection functions respectively for the pairing function .

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References

  1. Statman, Rick (1997), "On Cartesian monoids", Computer science logic (Utrecht, 1996), Lecture Notes in Computer Science, vol. 1258, Berlin: Springer, pp. 446–459, doi:10.1007/3-540-63172-0_55, MR   1611514 .