rule

tuprolog.solve.stdlib.rule

The rules of the standard library, i.e. its predicates written in Prolog.

Each constant is a rule with a signature (its name and arity in Prolog), and an implementation, i.e. the clause defining it; predicates defined by several clauses (append/3, member/2, ;/2) are classes grouping them. They are loaded by default in Prolog solvers.

Examples:

>>> Once.implementation
once(G_...) :- (ensure_executable(G_...), call(G_...), '!')
>>> Append.SIGNATURE
Signature(name=append, arity=3, vararg=false)

Arrow module-attribute

Arrow: Arrow = _rule.Arrow.INSTANCE

The rule of ->/2: if-then, i.e. (C -> T) proves T if C holds (once).

CurrentPrologFlag module-attribute

CurrentPrologFlag: CurrentPrologFlag = (
    _rule.CurrentPrologFlag.INSTANCE
)

The rule of current_prolog_flag/2: a flag and its value (see tuprolog.solve.flags).

Not module-attribute

Not: Not = _rule.Not.INSTANCE

The rule of not/1: negation as failure, like \+/1.

Once module-attribute

Once: Once = _rule.Once.INSTANCE

The rule of once/1: proves a goal, keeping its first solution only.

SetPrologFlag module-attribute

SetPrologFlag: SetPrologFlag = _rule.SetPrologFlag.INSTANCE

The rule of set_prolog_flag/2: sets the value of a flag.

Append

The rules of append/3: a list is the concatenation of two others.

Attributes:

Name	Type	Description
FUNCTOR		The name, append.
ARITY		The arity, 3.
SIGNATURE		The signature, append/3.
Base		The base case, append([], X, X).
Recursive		The recursive case, append([X | Y], Z, [X | W]) :- append(Y, Z, W).

Member

The rules of member/2: a term is an element of a list.

Attributes:

Name	Type	Description
FUNCTOR		The name, member.
ARITY		The arity, 2.
SIGNATURE		The signature, member/2.
Base		The base case, member(H, [H | _]).
Recursive		The recursive case, member(H, [_ | T]) :- member(H, T).

Semicolon

The rules of ;/2: disjunction (A ; B) and if-then-else ((C -> T ; E)).

Attributes:

Name	Type	Description
FUNCTOR		The name, ;.
ARITY		The arity, 2.
SIGNATURE		The signature, ;/2.
If		The rules of if-then-else: If.Then proves T if C holds (once), If.Else proves E otherwise.
Or		The rules of disjunction: Or.Left proves A, Or.Right proves B.

If

The rules of if-then-else, (C -> T ; E): Then and Else.

Or

The rules of disjunction, A ; B: Left and Right.