theorem
proved
term proof
eq_iff_toComplex_eq
show as:
view Lean formalization →
formal statement (Lean)
66theorem eq_iff_toComplex_eq {z w : LogicComplex} :
67 z = w ↔ toComplex z = toComplex w := by
proof body
Term-mode proof.
68 constructor
69 · exact congrArg toComplex
70 · intro h
71 have := congrArg fromComplex h
72 rw [fromComplex_toComplex, fromComplex_toComplex] at this
73 exact this
74
75/-! ## Algebra and coordinate transport -/
76
77instance : Zero LogicComplex := ⟨fromComplex 0⟩
78instance : One LogicComplex := ⟨fromComplex 1⟩
79instance : Add LogicComplex := ⟨fun z w => fromComplex (toComplex z + toComplex w)⟩
80instance : Neg LogicComplex := ⟨fun z => fromComplex (-toComplex z)⟩
81instance : Sub LogicComplex := ⟨fun z w => fromComplex (toComplex z - toComplex w)⟩
82instance : Mul LogicComplex := ⟨fun z w => fromComplex (toComplex z * toComplex w)⟩
83instance : Inv LogicComplex := ⟨fun z => fromComplex (toComplex z)⁻¹⟩
84instance : Div LogicComplex := ⟨fun z w => fromComplex (toComplex z / toComplex w)⟩
85