English
If s ∩ mulSupport f = t ∩ mulSupport f, then the finprod over s of f equals the finprod over t of f.
Русский
Если s ∩ mulSupport f = t ∩ mulSupport f, то \\( \\prodᶠ i∈s f(i) = \\prodᶠ i∈t f(i) \\).
LaTeX
$$$\\displaystyle (s \\cap mulSupport(f)) = (t \\cap mulSupport(f)) \\;\\Rightarrow\\; \\prod\\ᶠ i \\in s, f(i) = \\prod\\ᶠ i \\in t, f(i)$$$
Lean4
@[to_additive]
theorem finprod_mem_inter_mulSupport_eq (f : α → M) (s t : Set α) (h : s ∩ mulSupport f = t ∩ mulSupport f) :
∏ᶠ i ∈ s, f i = ∏ᶠ i ∈ t, f i := by rw [← finprod_mem_inter_mulSupport, h, finprod_mem_inter_mulSupport]