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CombinatorialGames.Misere.PFreeBlocking

If A is a blocking universe then so is pf(A) = PFreeSubset A.

@[irreducible]

If G, H ∈ pf(B) with o(G) = L and H a Left end, then o(G + H) = L.

This is Davies, Miller, Milley (Lemma 4.1 on p. 24)

theorem GameForm.Strong.of_subset {p : Player} {A B : GameForm → Prop} {g : GameForm} (h_strong : Form.Strong B g p) (h_subset : ∀ (x : GameForm), A x → B x) :
@[reducible, inline]
noncomputable abbrev GameForm.Blocking.Plugged (g : GameForm) :
Equations
Instances For

    Left/Right mirror of plugged_mem, for a g that is a Left end but not a Right end.

    Left/Right mirror of reduction_plug_end_not_isEnd_left, for a g that is a Left end but not a Right end.

    Separation #

    theorem PFree.downlinked_of_not_isEnd_left {U : GameForm → Prop} [OutcomeStable U] [Form.Short U] [ShortUniverse U] [Form.HasInt U] {g h : GameForm} (h_g : PFreeSubset U g) (h_h : PFreeSubset U h) (h_g_not_isEnd : ¬Form.IsEnd Player.left g) (h_moves_g : ∀ gl ∈ Moves.moves Player.left g, ¬gl ≥m (PFreeSubset U)h) (h_moves_h : ∀ hr ∈ Moves.moves Player.right h, ¬g ≥m (PFreeSubset U)hr) :
    theorem PFree.downlinked_of_not_isEnd_right {U : GameForm → Prop} [OutcomeStable U] [Form.Short U] [ShortUniverse U] [Form.HasInt U] {g h : GameForm} (h_g : PFreeSubset U g) (h_h : PFreeSubset U h) (h_h_not_isEnd : ¬Form.IsEnd Player.right h) (h_moves_g : ∀ gl ∈ Moves.moves Player.left g, ¬gl ≥m (PFreeSubset U)h) (h_moves_h : ∀ hr ∈ Moves.moves Player.right h, ¬g ≥m (PFreeSubset U)hr) :
    theorem PFree.downlinked_intCast_of_not_leftMoves_misereGE {U : GameForm → Prop} [OutcomeStable U] [Form.Short U] [ShortUniverse U] [Form.HasInt U] {g : GameForm} {n : ℤ} (h_g : PFreeSubset U g) (h_not_left_end : ¬Form.IsEnd Player.left g) (h_n : 0 ≤ n) (h : ∀ gl ∈ Moves.moves Player.left g, ¬gl ≥m (PFreeSubset U)↑n) :

    The maintenance–proviso test is invariant under conjugation (negating and swapping both sides), which lets each *_right result be derived from its *_left/no-suffix counterpart.

    Comparison across universes #

    @[irreducible]

    Comparison modulo pf(V) implies comparison modulo the larger pf(U) on forms of pf(V).

    On forms of pf(V), comparison modulo pf(V) and modulo the larger pf(U) coincide, so pf(V) embeds in pf(U) as a preorder.