Language Help

Applet help

  • Propositional variables are upper-case letters, i.e. "A"..."Z", optionally followed by lower-case letters and digits, e.g. "A", "B12", "Proposition42"
  • The negation may be expressed by one of the strings "~", or "not", leading to propositions like "~A" or "not Proposition42".
  • The conjunction may be expressed by one of the strings "&", "^", "and", leading to propositions like "~P1 & Z10" or "~A and B".
  • The disjunction may be expressed by one of the strings "v" (the lower-case letter V), "|" or "or", leading to propositions like "~P1 v Z10", "~(~P1 & Z10) | ~Prop3" or "~A or B".
  • The conditional may be expressed by one of the strings "->", "=>", leading to propositions like "~P1 -> Z10" or "not (~P1 & Z10) => Prop4".
  • The biconditional may be expressed by one of the strings "<->", "<=>", "iff", leading to propositions like "~P1 <-> Z10", "(~P1 & Z10) <=> A" or "~A iff B".
  • Brackets may be used as needed. Both "(", ")" and "[", "]" are valid, although every open bracket must be matched by a closed bracket of the same type. Examples: "(P v Q) & R", "P & [Q v R]", "(P v Q) & [Q v R]".
  • You may omit brackets in which case the applet evaluates (from left to right) negations, conjunctions, disjunctions, conditionals and biconditionals. If you are unsure what this means or if you want to be in total control of everything, you should try to use brackets.