Saturday, January 3, 2009

Peirce and Bricken accommodated

(Corrected 4.01.09)

Both Peirce's alpha graphs and Bricken's boundary logic may be seamlessly accommodated into my logic algebra. For this I'll adopt following conventions into my notation:

1) Letters g and f signify any propositional formula (or graph).
2) Negation of a formula is expressed by enclosing this formula between ‹ and ›.
3) Appearance of a formula in odd depth of negation is marked by enclosing this formula between ≺ and ≻; in even depth (incl 0) -- between ≼ and ≽; in any depth (incl 0) -- between ⋘ and ⋙.
4) Contents of the negated formula are joined by conjunction or disjunction depending on immediate context of the negated formula, i.e. [‹g f›] = ‹[g f]› and (‹g f›) = ‹(g f)›.
5) When formula is true independently of the context, context markers may be dropped.
6) Default context (Blank sheet) is conjunctive (i.e. Peircean).

Now we can demonstrate equivalences of three systems:

Peirce αBricken BL
Tom
Basic formulas
ggg
‹g›‹g›‹g›
gf‹‹g›‹f››(gf) ⇔ [‹‹g›‹f››]
‹‹g›‹f››gf(‹‹g›‹f››) ⇔ [gf]
‹g‹f››‹g›f(‹g‹f››) ⇔ [‹g›f]
Transformations
⇔ ‹‹›‹›› ⇔ ‹‹›› ⇔ T‹›‹› ⇔ ‹› ⇔ T(‹‹›‹››) ⇔ (‹‹››) ⇔() ⇔ ○ ⇔ ⇔ [‹›] ⇔ [‹›‹›]
‹›‹› ⇔ ‹› ⇔ F ⇔ ‹‹›‹›› ⇔ ‹‹›› ⇔ F[‹‹›‹››] ⇔ [‹‹››] ⇔ [] ⇔ □ ⇔ (‹›) ⇔ (‹›‹›)
‹›g ⇔ ‹› ‹‹›g› ⇔ (‹›g) ⇔ □ ⇔ [‹‹›g›]
‹‹›g› ⇔ ‹›g ⇔ ‹› (‹‹›g›) ⇔ ○ ⇔ [‹›g]
‹‹g›› ⇔ g
‹‹g›› ⇔ g
‹‹g›› ⇔ g
≼gf≽ ⇒ ≼g≽≺gf≻ ⇒ ≺g≻(≼gf≽) ⇒ (≼g≽)
[≺gf≻] ⇒ [≺g≻]
≺g≻ ⇒ ≺gf≻≼g≽ ⇒ ≼gf≽(≺g≻) ⇒ (≺gf≻)
[≼g≽] ⇒ [≼gf≽]
g⋘f⋙ ⇔ g⋘gf⋙g⋘f⋙ ⇔ g⋘gf⋙g⋘f⋙ ⇔ g⋘gf⋙