Deductive Logic
Top-down reasoning that moves from general premises to specific conclusions. If the premises are true and the inference rules are valid, the conclusion necessarily follows. There is no room for guesswork.
Use it wherever a wrong answer is unacceptable and the domain can be specified precisely: enforcing invariants, type checking, proving constraints, verifying formal properties, and any step that must be auditable and reproducible.
- Sound and complete within the formal system
- Zero hallucination bound - the answer is entailed or it is not
- Fully deterministic and reproducible
- Every step is auditable as a chain of inferences
- Garbage in, garbage out - a false premise yields a false conclusion
- Brittle in underspecified or messy domains
- Cannot generate new knowledge, only make implicit facts explicit
- Proof search can be computationally expensive
Mechanics & applied example
Start from axioms and known-true premises, then apply sound inference rules (modus ponens, modus tollens, universal instantiation) to derive conclusions. In practice this maps to symbolic derivation, SAT/SMT solving for constraint proofs, and theorem proving over a formal model of the system.
Given the invariant 'every input that passes validation conforms to schema S' and the fact 'this input passed validation', the engine deduces 'this input conforms to schema S'. That is a hard guarantee the pipeline can assert, not a probabilistic guess.