theorem
proved
term proof
ratio_rigidity_iff
show as:
view Lean formalization →
formal statement (Lean)
92theorem ratio_rigidity_iff {adj : V → V → Prop}
93 (hconn : ∀ u v : V, Relation.ReflTransGen adj u v)
94 {x : V → ℝ} (hpos : ∀ v, 0 < x v) :
95 (∀ v w, adj v w → Jcost (x v / x w) = 0) ↔
96 (∀ v w : V, x v = x w) :=
proof body
Term-mode proof.
97 ⟨ratio_rigidity hconn hpos,
98 fun hconst v w _ => constant_implies_zero_cost (hconst v w) (hpos w)⟩
99
100/-! ### Corollary: edge cost characterizations -/
101
102/-- J(x_v/x_w) = 0 iff x_v = x_w, for positive x. -/