Propositional Logic

Formulas in propositional logic are composed of:

• Atoms or propositional variables : P, Q, S
• Connectives (in order of precedence):

  	Math	C	meaning
  Negation	¬ or ˜	!	not
  Conjunction	∧ (``wedge'')	&&	and
  Disjunction	∨ (``vee'')	||	or
  Implication	→ or ⊃	? :	implies, if-then
  	↔	==	iff (if and only if)
  			← ∧ →

• Constants:

  True or filled-in box	True
  □ (``box'')	False