14 lines
463 B
Markdown
14 lines
463 B
Markdown
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We reinvented Monads!
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A monad is a triplet `(M,⊙,η)` where
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- \\(M\\) an <span class="yellow">Endofunctor</span> (to type `a` associate `M a`)
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- \\(⊙:M×M→M\\) a <span class="yellow">nat. trans.</span> (i.e. `⊙::M (M a) → M a` ; `join`)
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- \\(η:I→M\\) a <span class="yellow">nat. trans.</span> (\\(I\\) identity functor ; `η::a → M a`)
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Satisfying
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- \\(M ⊙ (M ⊙ M) = (M ⊙ M) ⊙ M\\)
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- \\(η ⊙ M = M = M ⊙ η\\)
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