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List of rules

Introduction

SymbolReadsArgument Semantics
^IAnd Introductionfrom x, y deduce x ^ y
->IImplication Introductionfrom "assuming x deduces y", deduce x -> y
/IOr Introductionfrom x deduce x / ? or ? / x
~INot Introductionfrom "assuming original deduces bottom" deduce its negation
~~IDouble Negation Introductionfrom x deduce ~~x
FIFalsity Introductionfrom x and ~x deduce F
TITruth Introductionfrom nothing deduces T (but why would you do that?)
<->IEquivalence Introductionfrom x -> y and y -> x deduce x <-> y
existsIExists Introductionfrom 𝝓(x) deduce ∃a 𝝓(a)
forallIForall Introductionfrom "c deduces f(c)" deduce ∀x f(x)

Elimination

SymbolReadsArgument Semantics
^EAnd Eliminationfrom x ^ y deduce x (or y)
->EEmplication Eliminationfrom x -> y and x deduce y
/EOr Eliminationfrom x1 / x2, "assuming x1 deduces y", "assuming x2 deduces y", deduce y
~ENot Eliminationfrom x and ~x deduces F (same as FI)
~~EDouble Negation Eliminationfrom ~~x deduce x
FEFalsity Eliminationfrom F deduce anything
<->EEquivalence Eliminationfrom x <-> y and either side, deduce the other side
existsEExists Eliminationfrom ∃a 𝝓(a) and "𝝓(c) for some c deduces x", deduce x
forallEForall Eliminationfrom ∀x f deduce f[x/c]
forall->EForall Implication Eliminationfrom ∀x f(x) -> g(x) and f(c), deduces g(c)

Special

SymbolReadsArgument Semantics
LEMLaw of Excluded Middlefrom nothing deduce p / ~p
MTModus Tollensfrom x -> y and ~y, deduce ~x
PCProof by Contradictionfrom "assuming x deduces F", deduce ~x
reflrule of Reflectionfrom nothing deduce x = x
=subEquality Substitutionfrom a = b and f(a), deduce f(b)
symrule of Symmetryfrom a = b deduce b = a
forall I constforall I constintroduces a new free variable
givenGivengiven proposition / formula
premisePremisegiven proposition / formula
assAssumptionassume proposition / formula
tickTickfrom x deduce x (to improve readability)