Package-level declarations

The SolverFactory for :solve-problog, a ProbLog-style probabilistic logic programming engine built on top of ClassicSolverFactory's SLD-NF resolution.

The functor of ProbLog's probability-annotation operator, ::, used to attach a probability to a clause's or fact's head (e.g. 0.3::burglary. states that burglary holds with probability 0.3). Theories parsed with PROBLOG_OPERATORS in scope (see ProblogSolverFactory.defaultBuiltins) recognize this operator.

The Operator declaration for ANNOTATION_FUNCTOR: infix, right-associative (xfy), with priority 900 -- lower (binding tighter) than the :- neck operator, so that 0.3::burglary :- foo. parses as (0.3::burglary) :- foo. rather than 0.3::(burglary :- foo).

The full OperatorSet used by :solve-problog: OperatorSet.DEFAULT (standard Prolog operators) plus PROBLOG_SPECIFIC_OPERATORS. Theories and queries meant to use ProbLog's :: notation should be parsed with this operator set (e.g. theoryString.parseAsTheory(PROBLOG_OPERATORS), or equivalently ProblogSolverFactory.defaultBuiltins.operators).

The OperatorSet containing only the ProbLog-specific operators added on top of standard Prolog, i.e. ANNOTATION_OPERATOR.