Reorganize proofs to make 'Program' accessible to files in Language/

This commit is contained in:
2026-06-29 10:30:39 -05:00
parent 59afbdaf71
commit fe5098095a
5 changed files with 122 additions and 110 deletions

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@@ -3,64 +3,4 @@ import Spa.Language.Semantics
import Spa.Language.Graphs
import Spa.Language.Traces
import Spa.Language.Properties
import Mathlib.Data.Finset.Sort
import Mathlib.Data.String.Basic
namespace Spa
structure Program where
rootStmt : Stmt
/-- A memoized copy of the control-flow graph. This field is an
implementation detail to avoid re-computing `Graph.wrap` and `Stmt.cfg`
every time the program's control flow graph is needed -/
cfgCache : Thunk Graph := Thunk.mk fun _ => Graph.wrap rootStmt.cfg
namespace Program
variable (p : Program)
-- Runtime implementation of `cfg`: read the memoized graph.
private def cfgImpl : Graph := p.cfgCache.get
@[implemented_by cfgImpl]
def cfg : Graph := Graph.wrap p.rootStmt.cfg
abbrev State : Type := p.cfg.Index
def initialState : p.State := p.rootStmt.cfg.wrapInput
def finalState : p.State := p.rootStmt.cfg.wrapOutput
noncomputable def trace {ρ : Env} (h : EvalStmt [] p.rootStmt ρ) :
Trace p.cfg p.initialState p.finalState [] ρ := by
obtain i₁, h₁, i₂, h₂, tr := EndToEndTrace.wrap (Stmt.cfg_sufficient h)
rw [Graph.wrap_inputs, List.mem_singleton] at h₁
rw [Graph.wrap_outputs, List.mem_singleton] at h₂
subst h₁; subst h₂
exact tr
def vars : List String := p.rootStmt.vars.sort (· ·)
lemma vars_nodup : p.vars.Nodup := Finset.sort_nodup _ _
def states : List p.State := p.cfg.indices
lemma states_complete (s : p.State) : s p.states := p.cfg.mem_indices s
lemma states_nodup : p.states.Nodup := p.cfg.nodup_indices
def code (st : p.State) : Option BasicStmt := p.cfg.nodes st
def incoming (s : p.State) : List p.State := p.cfg.predecessors s
lemma incoming_initialState_eq_nil : p.incoming p.initialState = [] :=
Graph.wrap_predecessors_eq_nil p.rootStmt.cfg p.initialState
(by rw [Graph.wrap_inputs]; exact List.mem_singleton_self _)
lemma mem_incoming_of_edge {s₁ s₂ : p.State}
(h : (s₁, s₂) p.cfg.edges) : s₁ p.incoming s₂ :=
p.cfg.mem_predecessors_of_edge h
end Program
end Spa
import Spa.Language.Program

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@@ -25,6 +25,15 @@ indexing into a list.
-/
/-- Logically, when combining `Fin`s from two distinct pools,
the combination is disjoint. -/
lemma Fin.castAdd_ne_natAdd {n m : } (i : Fin n) (j : Fin m) :
Fin.castAdd m i Fin.natAdd n j := by
intro h
have := congrArg Fin.val h
simp only [Fin.coe_castAdd, Fin.coe_natAdd] at this
omega
/-- Bump the upper bound of a list of `Fin`s without changing their value. -/
def List.finCastAdd {n : } (l : List (Fin n)) (m : ) : List (Fin (n + m)) :=
l.map (Fin.castAdd m)
@@ -157,6 +166,22 @@ def singleton (a : α) : GGraph α where
def wrap (g : GGraph (Option β)) : GGraph (Option β) :=
singleton none g singleton none
/-- The input / entry node generated by `GGraph.wrap`. -/
def wrapInput (g : GGraph (Option β)) : (wrap g).Index :=
(0 : Fin 1).castAdd ((g singleton none).size)
/-- The output / exit node generated by `GGraph.wrap`. -/
def wrapOutput (g : GGraph (Option β)) : (wrap g).Index :=
Fin.natAdd 1 ((Fin.natAdd g.size (0 : Fin 1)))
/-- The `wrapInput` is, indeed, the graph's only input after `wrap`. -/
lemma wrap_inputs (g : GGraph (Option β)) :
(wrap g).inputs = [g.wrapInput] := rfl
/-- The `wrapInput` is, indeed, the graph's only output after `wrap`. -/
lemma wrap_outputs (g : GGraph (Option β)) :
(wrap g).outputs = [g.wrapOutput] := rfl
@[simp] lemma map_singleton (f : α β) (a : α) :
f <$> singleton a = singleton (f a) := rfl
@@ -205,6 +230,35 @@ lemma nodup_indices : g.indices.Nodup :=
def predecessors (idx : g.Index) : List g.Index :=
g.indices.filter (fun idx' => (idx', idx) g.edges)
/-- When sequencing (proven here with `Graph.singleton` on the left), no edges
exist from the right-hand graph back to the left. -/
private lemma not_mem_edges_castAdd_sequence {g₂ : GGraph (Option β)} (i : Fin 1)
(idx : (singleton none g₂).Index) :
((idx, i.castAdd g₂.size) : (singleton none g₂).Edge)
(singleton none g₂).edges := by
intro h
rcases List.mem_append.mp h with h' | h'
· rcases List.mem_append.mp h' with h'' | h''
· -- lifted edges of `singleton []`: there are none
simp [singleton, List.finCastAddProd] at h''
· -- lifted edges of g₂: targets are natAdd
obtain e, _, heq := List.mem_map.mp h''
exact Fin.castAdd_ne_natAdd i e.2 (congrArg Prod.snd heq).symm
· -- product edges: targets are natAdd'd inputs of g₂
obtain -, hb := List.mem_product.mp h'
obtain j, -, heq := List.mem_map.mp hb
exact Fin.castAdd_ne_natAdd i j heq.symm
/-- The input node of a graph after `Graph.wrap` has no predecessors. -/
lemma wrap_predecessors_eq_nil (g : GGraph (Option β)) (idx : (wrap g).Index)
(h : idx (wrap g).inputs) :
(wrap g).predecessors idx = [] := by
rw [wrap_inputs, List.mem_singleton] at h
subst h
rw [GGraph.predecessors, List.filter_eq_nil_iff]
intro idx' _
simpa using not_mem_edges_castAdd_sequence (g₂ := g singleton none) 0 idx'
/-- There's there's an edge between two nodes `idx₁` and `idx₂`,
then `idx₁` is the predecessor of `idx₂`. -/
lemma mem_predecessors_of_edge {idx₁ idx₂ : g.Index}
@@ -225,7 +279,7 @@ abbrev Graph : Type := GGraph (Option BasicStmt)
namespace Graph
export GGraph (overlay sequence loop singleton wrap loop_inputs loop_outputs)
export GGraph (overlay sequence loop singleton wrap loop_inputs loop_outputs wrapInput wrapOutput wrap_inputs wrap_outputs)
@[inherit_doc] scoped infixr:70 "" => GGraph.overlay
@[inherit_doc] scoped infixr:70 "" => GGraph.sequence

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@@ -0,0 +1,56 @@
import Spa.Language.Base
import Spa.Language.Semantics
import Spa.Language.Graphs
import Mathlib.Data.Finset.Sort
import Mathlib.Data.String.Basic
namespace Spa
structure Program where
rootStmt : Stmt
/-- A memoized copy of the control-flow graph. This field is an
implementation detail to avoid re-computing `Graph.wrap` and `Stmt.cfg`
every time the program's control flow graph is needed -/
cfgCache : Thunk Graph := Thunk.mk fun _ => Graph.wrap rootStmt.cfg
namespace Program
variable (p : Program)
-- Runtime implementation of `cfg`: read the memoized graph.
private def cfgImpl : Graph := p.cfgCache.get
@[implemented_by cfgImpl]
def cfg : Graph := Graph.wrap p.rootStmt.cfg
abbrev State : Type := p.cfg.Index
def vars : List String := p.rootStmt.vars.sort (· ·)
lemma vars_nodup : p.vars.Nodup := Finset.sort_nodup _ _
def states : List p.State := p.cfg.indices
lemma states_complete (s : p.State) : s p.states := p.cfg.mem_indices s
lemma states_nodup : p.states.Nodup := p.cfg.nodup_indices
def code (st : p.State) : Option BasicStmt := p.cfg.nodes st
def incoming (s : p.State) : List p.State := p.cfg.predecessors s
def initialState : p.State := Graph.wrapInput p.rootStmt.cfg
def finalState : p.State := Graph.wrapOutput p.rootStmt.cfg
lemma mem_incoming_of_edge {s₁ s₂ : p.State}
(h : (s₁, s₂) p.cfg.edges) : s₁ p.incoming s₂ :=
p.cfg.mem_predecessors_of_edge h
lemma incoming_initialState_eq_nil : p.incoming p.initialState = [] :=
GGraph.wrap_predecessors_eq_nil p.rootStmt.cfg p.initialState
(by rw [Graph.wrap_inputs]; exact List.mem_singleton_self _)
end Program
end Spa

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@@ -23,13 +23,6 @@ namespace Spa
open Graph
lemma Fin.castAdd_ne_natAdd {n m : } (i : Fin n) (j : Fin m) :
Fin.castAdd m i Fin.natAdd n j := by
intro h
have := congrArg Fin.val h
simp only [Fin.coe_castAdd, Fin.coe_natAdd] at this
omega
section Embeddings
variable {g₁ g₂ : Graph} {ρ₁ ρ₂ : Env}
@@ -246,49 +239,17 @@ noncomputable def Stmt.cfg_sufficient {s : Stmt} {ρ₁ ρ₂ : Env}
| whileFalse ρ e s _ =>
exact EndToEndTrace.loop_empty
/-- The input / entry node generated by `Graph.wrap`. -/
def Graph.wrapInput (g : Graph) : (Graph.wrap g).Index :=
(0 : Fin 1).castAdd ((g Graph.singleton none).size)
namespace Program
/-- The output / exit node generated by `Graph.wrap`. -/
def Graph.wrapOutput (g : Graph) : (Graph.wrap g).Index :=
Fin.natAdd 1 ((Fin.natAdd g.size (0 : Fin 1)))
noncomputable def trace (p : Program) {ρ : Env} (h : EvalStmt [] p.rootStmt ρ) :
Trace p.cfg p.initialState p.finalState [] ρ := by
obtain i₁, h₁, i₂, h₂, tr := EndToEndTrace.wrap (Stmt.cfg_sufficient h)
rw [Graph.wrap_inputs, List.mem_singleton] at h₁
rw [Graph.wrap_outputs, List.mem_singleton] at h₂
subst h₁; subst h₂
exact tr
/-- The `Graph.wrapInput` is, indeed, the graph's only input after `Graph.wrap`. -/
lemma Graph.wrap_inputs (g : Graph) :
(Graph.wrap g).inputs = [g.wrapInput] := rfl
end Program
/-- The `Graph.wrapInput` is, indeed, the graph's only output after `Graph.wrap`. -/
lemma Graph.wrap_outputs (g : Graph) :
(Graph.wrap g).outputs = [g.wrapOutput] := rfl
/-- When sequencing (proven here with `Graph.singleton` on the left), no edges
exist from the right-hand graph back to the left. -/
private lemma not_mem_edges_castAdd_sequence {g₂ : Graph} (i : Fin 1)
(idx : (Graph.singleton none g₂).Index) :
((idx, i.castAdd g₂.size) : (Graph.singleton none g₂).Edge)
(Graph.singleton none g₂).edges := by
intro h
rcases List.mem_append.mp h with h' | h'
· rcases List.mem_append.mp h' with h'' | h''
· -- lifted edges of `singleton []`: there are none
simp [Graph.singleton, List.finCastAddProd] at h''
· -- lifted edges of g₂: targets are natAdd
obtain e, _, heq := List.mem_map.mp h''
exact Fin.castAdd_ne_natAdd i e.2 (congrArg Prod.snd heq).symm
· -- product edges: targets are natAdd'd inputs of g₂
obtain -, hb := List.mem_product.mp h'
obtain j, -, heq := List.mem_map.mp hb
exact Fin.castAdd_ne_natAdd i j heq.symm
/-- The input node of a graph after `Graph.wrap` has no predecessors. -/
lemma Graph.wrap_predecessors_eq_nil (g : Graph) (idx : (Graph.wrap g).Index)
(h : idx (Graph.wrap g).inputs) :
(Graph.wrap g).predecessors idx = [] := by
rw [Graph.wrap_inputs, List.mem_singleton] at h
subst h
rw [GGraph.predecessors, List.filter_eq_nil_iff]
intro idx' _
simpa using not_mem_edges_castAdd_sequence (g₂ := g Graph.singleton none) 0 idx'
end Spa

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@@ -1,5 +1,6 @@
import Spa.Language.Semantics
import Spa.Language.Graphs
import Spa.Language.Program
/-!