SD+ Derivation Rules
All the Derivation Rules of SD and
Rules of Inference
Modus Tollens $(\text{MT})$
$\mathscr{P}\supset\mathscr{Q}$ | |
$\sim\mathscr{Q}$ | |
$\rhd$ | $\sim\mathscr{P}$ |
Hypothetical Syllogism $(\text{HS})$
$\mathscr{P}\supset\mathscr{Q}$ | |
$\mathscr{Q}\supset\mathscr{R}$ | |
$\rhd$ | $\mathscr{P}\supset\mathscr{R}$ |
Disjunctive Syllogism $(\text{DS})$
$\mathscr{P}\lor\mathscr{Q}$ | |
$\sim\mathscr{P}$ | |
$\rhd$ | $\mathscr{Q}$ |
$\mathscr{P}\lor\mathscr{Q}$ | |
$\sim\mathscr{Q}$ | |
$\rhd$ | $\mathscr{P}$ |
Rules of Replacement
Commutation $(\text{Com})$
\(
\mathscr{P}\;\&\;\mathscr{Q}
\;\lhd\rhd\;
\mathscr{Q}\;\&\;\mathscr{P}
\)
\(
\mathscr{P}\lor\mathscr{Q}
\;\lhd\rhd\;
\mathscr{Q}\lor\mathscr{P}
\)
Association $(\text{Assoc})$
\(
\mathscr{P}\;\&\;(\mathscr{Q}\;\&\;\mathscr{R})
\;\lhd\rhd\;
(\mathscr{P}\;\&\;\mathscr{Q})\;\&\;\mathscr{R}
\)
\(
\mathscr{P}\lor(\mathscr{Q}\lor\mathscr{R})
\;\lhd\rhd\;
(\mathscr{P}\lor\mathscr{Q})\lor\mathscr{R}
\)
Implication $(\text{Impl})$
\(
\mathscr{P}\supset\mathscr{Q}
\;\lhd\rhd\;
\sim\mathscr{P}\lor\mathscr{Q}
\)
Double Negation $(\text{DN})$
\(
\mathscr{P}
\;\lhd\rhd\;
\sim\sim\mathscr{P}
\)
De Morgan $(\text{DeM})$
\(
\sim(\mathscr{P}\;\&\;\mathscr{Q})
\;\lhd\rhd\;
\sim\mathscr{P}\,\lor\sim\mathscr{Q}
\)
\(
\sim(\mathscr{P}\lor\mathscr{Q})
\;\lhd\rhd\;
\sim\mathscr{P}\;\&\;\sim\mathscr{Q}
\)
Idempotence $(\text{Idem})$
\(
\mathscr{P}
\;\lhd\rhd\;
\mathscr{P}\;\&\;\mathscr{P}
\)
\(
\mathscr{P}
\;\lhd\rhd\;
\mathscr{P}\lor\mathscr{P}
\)
Transposition $(\text{Trans})$
\(
\mathscr{P}\supset\mathscr{Q}
\;\lhd\rhd\;
\sim\mathscr{Q}\supset\,\sim\mathscr{P}
\)
Exportation $(\text{Exp})$
\(
\mathscr{P}\supset(\mathscr{Q}\supset\mathscr{R})
\;\lhd\rhd\;
(\mathscr{P}\;\&\;\mathscr{Q})\supset\mathscr{R}
\)
Distribution $(\text{Dist})$
\(
\mathscr{P}\;\&\;(\mathscr{Q}\lor\mathscr{R})
\;\lhd\rhd\;
(\mathscr{P}\;\&\;\mathscr{Q})
\lor
(\mathscr{P}\;\&\;\mathscr{R})
\)
\( \mathscr{P}\lor(\mathscr{Q}\;\&\;\mathscr{R}) \;\lhd\rhd\; (\mathscr{P}\lor\mathscr{Q}) \;\&\; (\mathscr{P}\lor\mathscr{R}) \)
\( \mathscr{P}\lor(\mathscr{Q}\;\&\;\mathscr{R}) \;\lhd\rhd\; (\mathscr{P}\lor\mathscr{Q}) \;\&\; (\mathscr{P}\lor\mathscr{R}) \)
Equivalence $(\text{Equiv})$
\(
\mathscr{P}\equiv\mathscr{Q}
\;\lhd\rhd\;
(\mathscr{P}\supset\mathscr{Q})\;\&\;
(\mathscr{Q}\supset\mathscr{P})
\)
\(
\mathscr{P}\equiv\mathscr{Q}
\;\lhd\rhd\;
(\mathscr{P}\;\&\;\mathscr{Q})\lor
(\sim\mathscr{P}\;\&\;\sim\mathscr{Q})
\)