All proofs
Project-declaredLean 4.8.0 · mathlib@b5eba5954288

Cond bind le of forall le

Prob.cond_bind_le_of_forall_le

Plain-language statement

We can bound a cond bind uniformly in the first argument

Exact Lean statement

lemma cond_bind_le_of_forall_le {f : Prob α} {g : α → Prob β} {p q : β → Prop} {b : ℝ}
    (b0 : 0 ≤ b) (le : ∀ x, f.prob x ≠ 0 → (g x).cond p q ≤ b) : (f >>= g).cond p q ≤ b

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
lemma cond_bind_le_of_forall_le {f : Prob α} {g : α  Prob β} {p q : β  Prop} {b : }    (b0 : 0  b) (le :  x, f.prob x  0  (g x).cond p q  b) : (f >>= g).cond p q  b := by  simp only [cond]  by_cases fg0 : 0 < (f >>= g).pr q  · simp only [div_le_iff fg0]; simp only [pr, exp_const_mul, exp_bind]    apply exp_mono; intro x px; specialize le x px; simp only [exp_const_mul]    by_cases g0 : 0 < (g x).pr q    · simp only [cond, div_le_iff g0] at le; exact le    · replace g0 := le_antisymm (not_lt.mp g0) pr_nonneg; simp only [pr] at g0      simp only [g0, mul_zero]; nth_rewrite 2 [g0]      apply exp_mono; intro y _; simp only [ite_le_ite_iff]; exact And.right  · replace fg0 := le_antisymm (not_lt.mp fg0) pr_nonneg    simp only [fg0, div_zero, b0]
Project
debate
License
Apache-2.0
Commit
de3a6e500ae1
Source
Prob/Cond.lean:85-97

Reuse this declaration

Bring the exact result into your workflow

The import identifies the source module. Your project still needs the pinned package dependency shown on this page.

What this badge means

This completion status comes from the project or community source. It has not yet been represented here as an independent rebuild and axiom audit.

Continue in this project

Related declarations

Project-declaredLean 4.8.0

Alice pr le

alice_pr_le

Plain-language statement

Honest Alice has error ≥ e with probability ≤ q

probabilitycomplexity theoryinteractive protocols

Source project: debate

Person-level attribution pending.

View proof record
Project-declaredLean 4.8.0

Alice steps cost

alice_steps_cost

Plain-language statement

Alice makes few queries, regardless of Bob and Vera

probabilitycomplexity theoryinteractive protocols

Source project: debate

Person-level attribution pending.

View proof record
Project-declaredLean 4.8.0

Alices close

alices_close

Plain-language statement

Alice produces (p,y) with p close to o.probs y with good probability

probabilitycomplexity theoryinteractive protocols

Source project: debate

Person-level attribution pending.

View proof record