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  "body": "\n## Summary\n\nThe ternary discriminator on a set $A$ is the operation $t(x, y, z)$ that returns $z$ when $x = y$ and returns $x$ otherwise.\nIt tests whether two elements are equal and chooses its output accordingly.\nAlgebras in which this operation is a term operation are called quasi-primal when they are finite.\nClasses of algebras sharing a term for it generate [[discriminator varieties|MC9MX40Z7S]], which have a very clear structure theory.\n\n## Explanations\n\n### L1 human\n\nThe discriminator is an \"if equal, then this, else that\" operation.\nIt looks at its first two arguments: if they are the same, it outputs the third, and if they differ, it outputs the first.\nOn $\\set{0, 1, 2}$, for example, $t(1, 1, 2) = 2$ and $t(1, 0, 2) = 1$.\nMany logical and algebraic structures can express this test with their own operations, and this has strong consequences.\n",
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