English
An abbreviation named prodToProdTopI is defined to express the induced map on the product of two spaces (via a universal property for the product of base objects) using a pairing of paths p₁ and p₂.
Русский
Задано сокращение prodToProdTopI, выражающее индуцированное отображение на произведении двух пространств через пару путей p₁, p₂.
LaTeX
$$abbrev prodToProdTopI {a₁ a₂} {b₁ b₂} (p₁ : fromTop a₁ ⟶ fromTop a₂) (p₂ : fromTop b₁ ⟶ fromTop b₂) := (prodToProdTop ...).map (X := (⟨a₁⟩, ⟨b₁⟩)) (Y := (⟨a₂⟩, ⟨b₂⟩)) (p₁, p₂)$$
Lean4
/-- The induced map of the left projection map X × Y → X -/
def projLeft : πₓ (TopCat.of (A × B)) ⥤ πₓ A :=
πₘ (TopCat.ofHom ⟨_, continuous_fst⟩)