def
definition
phiRing_comp
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IndisputableMonolith.Algebra.RecognitionCategory on GitHub at line 505.
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depends on
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used by
formal source
502 map_phi := rfl
503
504/-- Composition of `PhiRing` morphisms. -/
505def phiRing_comp {A B C : PhiRingObj} (g : PhiRingHom B C) (f : PhiRingHom A B) :
506 PhiRingHom A C where
507 map := g.map ∘ f.map
508 map_zero := by
509 change g.map (f.map A.zero) = C.zero
510 rw [f.map_zero]
511 exact g.map_zero
512 map_one := by
513 change g.map (f.map A.one) = C.one
514 rw [f.map_one]
515 exact g.map_one
516 map_add := by
517 intro a b
518 simp [Function.comp, f.map_add, g.map_add]
519 map_neg := by
520 intro a
521 simp [Function.comp, f.map_neg, g.map_neg]
522 map_mul := by
523 intro a b
524 simp [Function.comp, f.map_mul, g.map_mul]
525 map_phi := by
526 change g.map (f.map A.phi) = C.phi
527 rw [f.map_phi]
528 exact g.map_phi
529
530/-- The canonical object of the `PhiRing` category is `ℤ[φ]`. -/
531def canonicalPhiRingObj : PhiRingObj where
532 Carrier := PhiRing.PhiInt
533 zero := PhiRing.PhiInt.zero
534 one := PhiRing.PhiInt.one
535 add := PhiRing.PhiInt.add