Boolactual

Boolactual is a theoretical construct in programming languages that augments the boolean type with provenance information about how its value was computed. In languages that implement boolactual, a boolean value is modeled as a tagged pair consisting of the actual boolean value (true or false) and a provenance tag describing its origin. Provenance can indicate literals, comparison results, outcomes of logical or arithmetic operations, or type conversions. The primary aim is to provide visibility into the derivation of truth values for debugging, verification, and data provenance.

Semantics: Operators on boolactual values propagate provenance tags according to defined rules. Negation inverts the boolean component and updates the provenance to reflect a logical negation. Binary operations combine the provenance of operands through a joining or widening mechanism. The exact rules vary by language or analysis framework, but the goal is to retain origin information while computing the new boolean result.

Usage: Boolactual supports static analysis and debugging by enabling checks such as whether a boolean originated from a trusted literal or from user input. It can also aid tracing the source of a condition during program review.

Limitations: The approach adds runtime or compile-time overhead and increases type complexity. Adoption requires language or tooling support, and interoperability with existing boolean APIs may be challenging.

See also: boolean type, data provenance, refinement types, dependent types.