pyk.kast.manip module

abstract_term_safely(kast: KInner, base_name: str = 'V', sort: KSort | None = None, existing_var_names: set[str] | None = None) → KVariable

apply_existential_substitutions(state: KInner, constraints: Iterable[KInner]) → tuple[KInner, Iterable[KInner]]

bool_to_ml_pred(kast: KInner) → KInner

build_claim(claim_id: str, init_config: KInner, final_config: KInner, init_constraints: Iterable[KInner] = (), final_constraints: Iterable[KInner] = (), keep_vars: Iterable[str] = ()) → tuple[KClaim, Subst]

Return a KClaim between the supplied initial and final states.

Parameters:

• claim_id – Label to give the claim.

• init_config – State to put on LHS of the rule.

• final_config – State to put on RHS of the rule.

• init_constraints – Constraints to use as requires clause.

• final_constraints – Constraints to use as ensures clause.

• keep_vars – Variables to leave in the side-conditions even if not bound in the configuration.

Returns:

A tuple (claim, var_map) where

• claim: A KClaim with variable naming conventions applied so that it should be parseable by the K Frontend.

• var_map: The variable renamings applied to make the claim parseable by the K Frontend (which can be undone to recover the original variables).

build_rule(rule_id: str, init_config: KInner, final_config: KInner, init_constraints: Iterable[KInner] = (), final_constraints: Iterable[KInner] = (), priority: int | None = None, keep_vars: Iterable[str] = (), defunc_with: KDefinition | None = None) → tuple[KRule, Subst]

Return a KRule between the supplied initial and final states.

Parameters:

• rule_id – Label to give the rule.

• init_config – State to put on LHS of the rule.

• final_config – State to put on RHS of the rule.

• init_constraints – Constraints to use as requires clause.

• final_constraints – Constraints to use as ensures clause.

• priority – Priority index to assign to generated rules.

• keep_vars – Variables to leave in the side-conditions even if not bound in the configuration.

• defunc_with – KDefinition for filtering out function symbols on LHS of rules.

Returns:

A tuple (rule, var_map) where

• rule: A KRule with variable naming conventions applied so that it should be parseable by the K Frontend.

• var_map: The variable renamings applied to make the rule parseable by the K Frontend (which can be undone to recover the original variables).

cell_label_to_var_name(label: str) → str

Return a variable name based on a cell label.

collapse_dots(kast: KInner) → KInner

Given a configuration with structural frames …, minimize the structural frames needed.

Parameters:

kast – A configuration, potentially with structural frames.

Returns:

The same configuration, with the amount of structural framing minimized.

count_vars(term: KInner) → Counter[str]

defunctionalize(defn: KDefinition, kinner: KInner) → tuple[KInner, list[KInner]]

Turn non-constructor arguments into side-conditions so that a term is only constructor-like.

Parameters:

• defn – The definition to pull function label information from.

• kinner – The term to defunctionalize.

Returns:

A tuple of the defunctionalized term and the list of constraints generated.

extract_cells(kast: KInner, keep_cells: Collection[str]) → KInner

extract_lhs(term: KInner) → KInner

extract_rhs(term: KInner) → KInner

extract_subst(term: KInner) → tuple[Subst, KInner]

free_vars(kast: KInner) → frozenset[str]

if_ktype(ktype: type[KI], then: Callable[[KI], KInner]) → Callable[[KInner], KInner]

inline_cell_maps(kast: KInner) → KInner

Ensure that cell map collections are printed nicely, not as Maps.

Parameters:

kast – A KAST term.

Returns:

The KAST term with cell maps inlined.

is_anon_var(kast: KInner) → bool

is_spurious_constraint(term: KInner) → bool

is_term_like(kast: KInner) → bool

labels_to_dots(kast: KInner, labels: Collection[str]) → KInner

Abstract specific labels for printing.

Parameters:

• kast – A term.

• labels – List of labels to abstract.

Returns

The term with labels abstracted.

minimize_rule_like(rule: RL, keep_vars: Iterable[str] = ()) → RL

Minimize a K rule or claim for pretty-printing.

• Variables only used once will be removed.

• Unused cells will be abstracted.

• Useless side-conditions will be attempted to be removed.

Parameters:

rule – A K rule or claim.

Returns:

The rule or claim, minimized.

minimize_term(term: KInner, keep_vars: Iterable[str] = (), abstract_labels: Collection[str] = (), keep_cells: Collection[str] = ()) → KInner

Minimize a K term for pretty-printing.

• Variables only used once will be removed.

• Unused cells will be abstracted.

• Useless conditions will be attempted to be removed.

Parameters:

kast – A term.

Returns:

The term, minimized.

ml_pred_to_bool(kast: KInner, unsafe: bool = False) → KInner

no_cell_rewrite_to_dots(term: KInner) → KInner

Transform a given term by replacing the contents of each cell with dots if the LHS and RHS are the same.

This function recursively traverses the cells in a term. When it finds a cell whose left-hand side (LHS) is identical to its right-hand side (RHS), it replaces the cell’s contents with a predefined DOTS.

Parameters:

term – The term to be transformed.

Returns:

The transformed term, where specific cell contents have been replaced with dots.

normalize_constraints(constraints: Iterable[KInner]) → tuple[KInner, ...]

normalize_ml_pred(pred: KInner) → KInner

on_attributes(kast: W, f: Callable[[KAtt], KAtt]) → W

propagate_up_constraints(k: KInner) → KInner

push_down_rewrites(kast: KInner) → KInner

remove_attrs(term: KInner) → KInner

remove_generated_cells(term: KInner) → KInner

Remove <generatedTop> and <generatedCounter> from a configuration.

Parameters:

term – A term.

Returns:

The term with those cells removed.

remove_semantic_casts(kast: KInner) → KInner

Remove injected #SemanticCast* nodes in AST.

Parameters:

kast – A term (possibly) containing automatically injected #SemanticCast* KApply nodes.

Returns:

The term without the #SemanticCast* nodes.

remove_source_map(definition: KDefinition) → KDefinition

remove_useless_constraints(constraints: Iterable[KInner], initial_vars: Iterable[str]) → list[KInner]

Remove constraints that do not depend on a given iterable of variables (directly or indirectly).

Parameters:

• constraints – Iterable of constraints to filter.

• initial_vars – Initial iterable of variables to keep constraints for.

Returns:

A list of constraints with only those constraints that contain the initial variables, or variables that depend on those through other constraints in the list.

rename_generated_vars(term: KInner) → KInner

replace_rewrites_with_implies(kast: KInner) → KInner

set_cell(constrained_term: KInner, cell_variable: str, cell_value: KInner) → KInner

simplify_bool(k: KInner) → KInner

sort_ac_collections(kast: KInner) → KInner

sort_assoc_label(label: str, kast: KInner) → KInner

split_config_and_constraints(kast: KInner) → tuple[KInner, KInner]

split_config_from(configuration: KInner) → tuple[KInner, dict[str, KInner]]

Split the substitution from a given configuration.

Given an input configuration config, will return a tuple (symbolic_config, subst), where:

1. config == substitute(symbolic_config, subst)

2. symbolic_config is the same configuration structure, but where the contents of leaf cells is replaced with a fresh KVariable.

3. subst is the substitution for the generated KVariables back to the original configuration contents.

undo_aliases(definition: KDefinition, kast: KInner) → KInner

useless_vars_to_dots(kast: KInner, keep_vars: Iterable[str] = ()) → KInner

Structurally abstract away useless variables.

Parameters:

• kast – A term.

• keep_vars – Iterable of variables to keep.

Returns:

The term with the useless varables structurally abstracted.