Laws of form

Alfred North Whitehead Alonzo Church already Amer appear argument arrangement axiom Boolean algebras boundary calculus of indications called Cambridge cancellation canon Chapter Charles Sanders Peirce circle circumference condensation connexion consequence consider constant constructed cross r cross deepest space degree demonstration distinct variables distinguished Edward V Huntington empty cross evident example existence existential experience fact finite formal George Boole George Spencer-Brown given hitherto hypothesis of simplification identical illustrated implication indicate the marked injunction inside interpretation justified Kurt Godel Ludwig Wittgenstein marker mathe mathematical matical number of crosses number of steps oscillation ourselves plane possible premisses primary algebra primary arithmetic primitive equation principle procedure proposition prove R D Laing reader reference seen sentential calculus Sheffer's simple expression Spencer Brown stage stand statements substitution Suppose syllogism tion token transcribed true universal unmarked valid wave structure Whitehead Wittgenstein write Yehoshua Bar-Hillel