natural deduction
Logical inference system
Natural deduction is a system of logical proof that mirrors how people actually reason, building arguments step by step from assumptions to conclusions.
Rather than manipulating symbols through abstract rules, it uses intuitive operations like assuming something temporarily to see what follows, then discharging that assumption.
The proof proceeds by natural deduction, first assuming P, then deriving Q.
The method dominates logic education because its structure feels more like ordinary thinking than axiomatic systems.
Proof system using sequents
- derivationSource or origin tracing
- assumptionUnverified belief accepted as true
- dischargeRelease of substance outward
- reductio ad absurdumDisproof by absurd consequence
flag · scope · reiteration · premise
Reliability of structure
- completenessState of being whole
- validityQuality of being sound
- consistencyReliable adherence to standards
- decidabilityAlgorithmic resolution capability
Word joining clauses together
- simplificationMaking something less complex
- additionJoining quantities mathematically
- absorptionProcess of taking in
- exportationSending goods overseas
sequent calculus
Proof system using sequents
- derivationSource or origin tracing
- assumptionUnverified belief accepted as true
- dischargeRelease of substance outward
reductio ad absurdum · flag · scope · reiteration · premise
soundness
Reliability of structure
- completenessState of being whole
- validityQuality of being sound
- consistencyReliable adherence to standards
conjunction
Word joining clauses together
- simplificationMaking something less complex
- additionJoining quantities mathematically
- absorptionProcess of taking in
exercise
Activity for fitness
- logicpremise, premises, conclusion, conclusions, inference
- Formal Methodsspecifications, invariants, preconditions, soundness, completeness
- Constructive Logicintuitionism, Heyting algebra, constructivism, double negation, sequent calculus
- formal systemsformal logic, axioms, postulates, derivation, proofs
- Proof Theoryproof, theorem, axiom, lemma, corollary
- proofsproof by contradiction, contrapositive, contradiction, theorem, lemma
natural, deduction, unnatural, supernatural, naturalness, unnaturally, naturalist, naturalistic, naturalize