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▲✐st❛ ❞❡ ❊①❡r❝í❝✐♦s ✶✿ ❙♦❧✉çõ❡s ❋✉♥❞❛♠❡♥t♦s ❞❛ ▲ó❣✐❝❛ ✕ ▲ó❣✐❝❛ Pr♦♣♦s✐❝✐♦♥❛❧ ❯❋▼●✴■❈❊①✴❉❈❈ ❉❈❈✶✶✶ ✕ ▼❛t❡♠át✐❝❛ ❉✐s❝r❡t❛ ❈✐ê♥❝✐❛s ❊①❛t❛s ✫ ❊♥❣❡♥❤❛r✐❛s ✶♦ ❙❡♠❡str❡ ❞❡ ✷✵✶✼ ✶✳ ❈♦♥str✉❛ ❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡ ♣❛r❛ ❛ s❡❣✉✐♥t❡ ♣r♦♣♦s✐çã♦✿ E = (p ∨ (¬p ∨ q)) ∧ ¬(q ∧ ¬r) ❘❡s♣♦st❛✿ p q r (p ∨ (¬p ∨ q)) ¬(q ∧ ¬r) E ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ✷✳ ▼♦str❡ s❡ ❛s ❡①♣r❡ssõ❡s E1 ❡ E2 sã♦ ❡q✉✐✈❛❧❡♥t❡s ❧♦❣✐❝❛♠❡♥t❡✿ E1 = (s→ (p ∧ ¬r)) ∧ ((p→ (r ∨ q)) ∧ s) E2 = (p ∧ q ∧ ¬r ∧ s) ∨ ¬(p ∨ s) ❘❡s♣♦st❛✿ p q r s (s → (p ∧ ¬r)) ((p → (r ∨ q)) ∧ s) E1 (p ∧ q ∧ ¬r ∧ s) ¬(p ∨ s) E2 ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❈♦♠♦ ❛s ❞✉❛s t❛❜❡❧❛s ❞❛ ✈❡r❞❛❞❡ ♥ã♦ sã♦ ✐❞ê♥t✐❝❛s✱ ❛s ❡①♣r❡ssõ❡s E1 ❡ E2 ♥ã♦ sã♦ ❡q✉✐✈❛❧❡♥t❡s ❧♦❣✐❝❛♠❡♥t❡✳ ✶ ✸✳ ❋❛ç❛ ❛ s✐♠♣❧✐✜❝❛çã♦ ❧ó❣✐❝❛ ❞❛ s❡❣✉✐♥t❡ ❡①♣r❡ssã♦ ✉s❛♥❞♦ ❛♣❡♥❛s ❛s ❧❡✐s ❞❛ ❧ó❣✐❝❛✿ (p ∧ (¬(¬p ∨ q))) ∨ (p ∧ q) ❘❡s♣♦st❛✿ (p ∧ (¬(¬p ∨ q))) ∨ (p ∧ q) ❉❡ ▼♦r❣❛♥ s♦❜r❡ ¬(¬p ∨ q)✳ (p ∧ (p ∧ ¬q)) ∨ (p ∧ q) ❆ss♦❝✐❛t✐✈✐❞❛❞❡ s♦❜r❡ p ∧ (p ∧ ¬q)✳ ((p ∧ p) ∧ ¬q) ∨ (p ∧ q) ■❞❡♠♣♦tê♥❝✐❛ s♦❜r❡ p ∧ p✳ (p ∧ ¬q) ∨ (p ∧ q) ❉✐str✐❜✉t✐✈✐❞❛❞❡ s♦❜r❡ ❛ ❡①♣r❡ssã♦✳ p ∧ (¬q ∨ q) ◆❡❣❛çã♦ s♦❜r❡ ¬q ∨ q✳ p ∧ t ■❞❡♥t✐❞❛❞❡ ❝♦♠ ❛ t❛✉t♦❧♦❣✐❛ t✳ p ✹✳ ▼♦str❡ s❡ ♦ s❡❣✉✐♥t❡ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞♦ ♦✉ ♥ã♦ ✉s❛♥❞♦ ❛s ❢♦r♠❛s ✈á❧✐❞❛s ❞❡ ❛r❣✉♠❡♥t♦s✳ ❊♠ ❝❛❞❛ ♣❛ss♦✱ ✐❞❡♥t✐✜q✉❡ ❛ r❛③ã♦ ♣❛r❛ s❡ ♦❜t❡r ❛ ❝♦♥❝❧✉sã♦✿ ✭❛✮ ¬p→ r ∧ ¬s ✭❜✮ t→ s ✭❝✮ u→ ¬p ✭❞✮ ¬w ✭❡✮ u ∨ w ✭❢✮ ✳✳✳ ¬t ∨ w ❘❡s♣♦st❛✿ ❉❡❞✉çõ❡s✿ ✭✐✮ u ∨ w ✭❡✮ ¬w ✭❞✮ ✳✳✳ u ❙✐❧♦❣✐s♠♦ ❉✐s❥✉♥t✐✈♦ ✭✐✐✮ u→ ¬p ✭❝✮ u ✭✐✮ ✳✳✳ ¬p ▼♦❞✉s P♦♥❡♥s ✭✐✐✐✮ ¬p→ r ∧ ¬s ✭❛✮ ¬p ✭✐✐✮ ✳✳✳ r ∧ ¬s ▼♦❞✉s P♦♥❡♥s ✭✐✈✮ r ∧ ¬s ✭✐✐✐✮ ✳✳✳ ¬s ❙✐♠♣❧✐✜❝❛çã♦ ❈♦♥❥✉♥t✐✈❛ ✭✈✮ t→ s ✭❜✮ ¬s ✭✐✈✮ ✳✳✳ ¬t ▼♦❞✉s ❚♦❧❧❡♥s ✭✈✐✮ ¬t ✭✈✮ ✳✳✳ ¬t ∨ w ❆❞✐çã♦ ❉✐s❥✉♥t✐✈❛ ❆ ❢♦r♠❛ ❞❡ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞❛✳ ✺✳ ❊st❡ ❡①❡r❝í❝✐♦ é ✏♣r❛t✐❝❛♠❡♥t❡ ✐❞ê♥t✐❝♦✑ ❛♦ ❛♥t❡r✐♦r ❡①❝❡t♦ q✉❡ ❛ ❝♦♥❝❧✉sã♦ é ✉♠ ✏♣♦✉❝♦ ❞✐❢❡r❡♥t❡✑✳ ▼♦str❡ s❡ ♦ s❡❣✉✐♥t❡ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞♦ ♦✉ ♥ã♦ ✉s❛♥❞♦ ❛s ❢♦r♠❛s ✈á❧✐❞❛s ❞❡ ❛r❣✉♠❡♥t♦s✳ ❊♠ ❝❛❞❛ ♣❛ss♦✱ ✐❞❡♥t✐✜q✉❡ ❛ r❛③ã♦ ♣❛r❛ s❡ ♦❜t❡r ❛ ❝♦♥❝❧✉sã♦✿ ✭❛✮ ∼p→ r ∧ ∼s ✷ ✭❜✮ t→ s ✭❝✮ u→ ∼s ✭❞✮ ∼w ✭❡✮ u ∨ w ✭❢✮ ✳✳✳ ∼t ∧ w ❘❡s♣♦st❛✿ ❉❡❞✉çõ❡s✿ ✭✐✮ u ∨ v ✭❡✮ ∼w ✭❞✮ ✳✳✳ u ❙✐❧♦❣✐s♠♦ ❉✐s❥✉♥t✐✈♦ ✭✐✐✮ u→ ∼s ✭❝✮ u ✭✐✮ ✳✳✳ ∼s ▼♦❞✉s P♦♥❡♥s ✭✐✐✐✮ t→ s ✭❜✮ ∼s ✭✐✐✮ ✳✳✳ ∼t ▼♦❞✉s ❚♦❧❧❡♥s ❆ ♣r❡♠✐ss❛ ✭❛✮ ♣♦ss✉✐ ❛s ✈❛r✐á✈❡✐s p ❡ r q✉❡ ♥ã♦ ❡stã♦ ♣r❡s❡♥t❡s ♥❛s ♦✉tr❛s ♣r❡♠✐ss❛s✳ ❆ss✐♠✱ ♥❛❞❛ ♣♦❞❡ s❡r ❞✐t♦✳ ❆ ❝♦♥❝❧✉sã♦ ❞♦ ❛r❣✉♠❡♥t♦ ✭❢✮ ♣♦ss✉✐ ❞♦✐s t❡r♠♦s✿ ∼t✱ q✉❡ s❛❜❡✲s❡ s❡r ✈❡r❞❛❞❡✐r♦ ✭✐✐✐✮✱ ❡ w✱ q✉❡ ♥❡❣❛ ❛ ♣r❡♠✐ss❛ ✭❞✮✳ ❆ss✐♠✱ ❛ ❝♦♥❝❧✉sã♦ ❡stá ❡rr❛❞❛ ❡ ❛ ❢♦r♠❛ ❞❡ ❛r❣✉♠❡♥t♦ é ✐♥✈á❧✐❞❛✳ ❊ss❛ ❝♦♥❝❧✉sã♦ t❛♠❜é♠ ♣♦❞❡ s❡r ✈✐st❛ ✉s❛♥❞♦ ❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡ ❛❜❛✐①♦✳ ❊①✐st❡♠ três ❧✐♥❤❛s ❝rít✐❝❛s✿ ✶✹✱ ✸✵ ❡ ✹✻✱ q✉❡ ♣♦ss✉❡♠ ❝♦♥❝❧✉sã♦ ❢❛❧s❛✳ ■ss♦ ❞❡♠♦♥str❛ q✉❡ ❛ ❢♦r♠❛ ❞❡ ❛r❣✉♠❡♥t♦ é ✐♥✈á❧✐❞❛✳ ✸ p r s t u w ∼p → r ∧ ∼s t → s u → ∼s ∼w u ∨ w ∼t ∧ w ✶✳ ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ✷✳ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ✸✳ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ✹✳ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✺✳ ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❱ ✻✳ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ✼✳ ❱ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ✽✳ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✾✳ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✶✵✳ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❱ ❋ ✶✶✳ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✶✷✳ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❋ ✶✸✳ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❱ → ✶✹✳ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ✶✺✳ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ✶✻✳ ❱ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✶✼✳ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ✶✽✳ ❱ ❋ ❱ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ✶✾✳ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ✷✵✳ ❱ ❋ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✷✶✳ ❱ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❱ ✷✷✳ ❱ ❋ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ✷✸✳ ❱ ❋ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ✷✹✳ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✷✺✳ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✷✻✳ ❱ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❱ ❋ ✷✼✳ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✷✽✳ ❱ ❋ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❋ ✷✾✳ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❱ → ✸✵✳ ❱ ❋ ❋ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ✸✶✳ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ✸✷✳ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✸✸✳ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ✸✹✳ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ✸✺✳ ❋ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ✸✻✳ ❋ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ✸✼✳ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❱ ✸✽✳ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ✸✾✳ ❋ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ✹✵✳ ❋ ❱ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ✹✶✳ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✹✷✳ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❱ ❋ ✹✸✳ ❋ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ✹✹✳ ❋ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❋ ✹✺✳ ❋ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❱ → ✹✻✳ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ✹✼✳ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❱ ✹✽✳ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❋ ✹✾✳ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ✺✵✳ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ✺✶✳ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ✺✷✳ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ✺✸✳ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❋ ❋ ❱ ❱ ✺✹✳ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ✺✺✳ ❋ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ✺✻✳ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ✺✼✳ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❋ ✺✽✳ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ✺✾✳ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❱ ❋ ✻✵✳ ❋ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ✻✶✳ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ✻✷✳ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ✻✸✳ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ✻✹✳ ❋ ❋ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ✻✳ ❖ ❢❛♠♦s♦ ❞❡t❡t✐✈❡ P❡r❝✉❧❡ ❍♦✐r♦t ❢♦✐ ❝❤❛♠❛❞♦ ♣❛r❛ r❡s♦❧✈❡r ✉♠ ❛ss❛ss✐♥❛t♦ ♠✐st❡r✐♦s♦✳ ❊❧❡ ❞❡t❡r♠✐♥♦✉ ♦s s❡❣✉✐♥t❡s ❢❛t♦s✿ ✭❛✮ ▲♦r❞ ❈❤❛r❧❡s✱ ♦ ❤♦♠❡♠ ❛ss❛ss✐♥❛❞♦✱ ❢♦✐ ♠♦rt♦ ❝♦♠ ✉♠❛ ♣❛♥❝❛❞❛ ♥❛ ❝❛❜❡ç❛ ❝♦♠ ✉♠ ❝❛st✐ç❛❧✳ ✭❜✮ ❖✉ ▲❛❞② ❈❛♠✐❧❛ ♦✉ ❛ ❡♠♣r❡❣❛❞❛ ❙❛r❛ ❡st❛✈❛♠ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✳ ✹ ✭❝✮ ❙❡ ♦ ❝♦③✐♥❤❡✐r♦ ❡st❛✈❛ ♥❛ ❝♦③✐♥❤❛ ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✱ ❡♥tã♦ ♦ ❛ç♦✉❣✉❡✐r♦ ♠❛t♦✉ ▲♦r❞ ❈❤❛r❧❡s ❝♦♠ ✉♠❛ ❞♦s❡ ❢❛t❛❧ ❞❡ ❛rsê♥✐❝♦✳ ✭❞✮ ❙❡ ▲❛❞② ❈❛♠✐❧❛ ❡st❛✈❛ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✱ ❡♥tã♦ ♦ ♠♦t♦r✐st❛ ♠❛t♦✉ ▲♦r❞ ❈❤❛r❧❡s✳ ✭❡✮ ❙❡ ♦ ❝♦③✐♥❤❡✐r♦ ♥ã♦ ❡st❛✈❛ ♥❛ ❝♦③✐♥❤❛ ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✱ ❡♥tã♦ ❙❛r❛ ♥ã♦ ❡st❛✈❛ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r q✉❛♥❞♦ ♦ ❛ss❛ss✐♥❛t♦ ♦❝♦rr❡✉✳ ✭❢✮ ❙❡ ❙❛r❛ ❡st❛✈❛ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✱ ❡♥tã♦ ♦ ❛❥✉❞❛♥t❡ ♣❡ss♦❛❧ ❞❡ ▲♦r❞ ❈❤❛r❧❡s ♦ ♠❛t♦✉✳ ➱ ♣♦ssí✈❡❧ ♣❛r❛ ♦ ❞❡t❡t✐✈❡ P❡r❝✉❧❡ ❍♦✐r♦t ❞❡❞✉③✐r q✉❡♠ ♠❛t♦✉ ▲♦r❞❡ ❈❤❛r❧❡s❄ ❙❡ s✐♠✱ q✉❡♠ é ♦ ❛ss❛ss✐♥♦❄ ❘❡s♣♦st❛✿ ❙❡❥❛♠ ♦s s❡❣✉✐♥t❡s ❛r❣✉♠❡♥t♦s✿ p ❂ ▲♦r❞ ❈❤❛r❧❡s ❢♦✐ ♠♦rt♦ ❝♦♠ ✉♠❛ ♣❛♥❝❛❞❛ ♥❛ ❝❛❜❡ç❛ ❝♦♠ ✉♠ ❝❛st✐ç❛❧✳ q ❂ ▲❛❞② ❈❛♠✐❧❛ ❡st❛✈❛ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✳ r ❂ ❙❛r❛ ❡st❛✈❛ ♥❛ s❛❧❛ ❞❡ ❥❛♥t❛r ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✳ s ❂ ❈♦③✐♥❤❡✐r♦ ❡st❛✈❛ ♥❛ ❝♦③✐♥❤❛ ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✳ t ❂ ❆ç♦✉❣✉❡✐r♦ ♠❛t♦✉ ▲♦r❞ ❈❤❛r❧❡s ❝♦♠ ✉♠❛ ❞♦s❡ ❢❛t❛❧ ❞❡ ❛rsê♥✐❝♦✳ u ❂ ▼♦t♦r✐st❛ ♠❛t♦✉ ▲♦r❞ ❈❤❛r❧❡s✳ v ❂ ❆❥✉❞❛♥t❡ ♣❡ss♦❛❧ ❞❡ ▲♦r❞ ❈❤❛r❧❡s ♦ ♠❛t♦✉✳ ❚r❛❞✉çã♦ ❞♦s ❢❛t♦s ♣❛r❛ ❛s ♣r♦♣♦s✐çõ❡s✿ ✭❛✮ p ✭❜✮ q ∨ r ✭❝✮ s→ t ✭❞✮ q → u ✭❡✮ ¬s→ ¬r ✭❢✮ r → v ❉❡❞✉çõ❡s✿ ✭✐✮ ❙✉♣♦♥❤❛ q✉❡ s s❡❥❛ ❱✱ ✐✳❡✳✱ ♦ ❝♦③✐♥❤❡✐r♦ ❡st❛✈❛ ♥❛ ❝♦③✐♥❤❛ ♥♦ ♠♦♠❡♥t♦ ❞♦ ❛ss❛ss✐♥❛t♦✳ s→ t ✭❝✮ s ✭❙✉♣♦s✐çã♦✮ ✳✳✳ t ▼♦❞✉s P♦♥❡♥s ✭✐✐✮ ◆♦ ❡♥t❛♥t♦✱ t→ ✏❝♦♥tr❛❞✐çã♦✑✱ ❥á q✉❡ ▲♦r❞ ❈❤❛r❧❡s ♥ã♦ ❢♦✐ ♠♦rt♦ ❝♦♠ ❛rsê♥✐❝♦ ❡ s✐♠ ♣♦r ✉♠❛ ♣❛♥❝❛❞❛ ♥❛ ❝❛❜❡ç❛ ✭❛✮✳ ▲♦❣♦✱ ❛ s✉♣♦s✐çã♦ q✉❡ ♦ ❝♦③✐♥❤❡✐r♦ ❡st❛✈❛ ♥❛ ❝♦③✐♥❤❛ é ❢❛❧s❛✳ ❆ss✐♠✱ t❡♠♦s ¬s✳ s→ t ✭❝✮ t→ ✏❝♦♥tr❛❞✐çã♦✑ ✭✐✮ ✳✳✳ ¬s ❙✐❧♦❣✐s♠♦ ❍✐♣♦tét✐❝♦ ❡ ❈♦♥tr❛❞✐çã♦ ✭✐✐✐✮ ¬s→ ¬r ✭❡✮ ¬s ✭✐✐✮ ✳✳✳ ¬r ▼♦❞✉s P♦♥❡♥s ✭✐✈✮ q ∨ r ✭❜✮ ¬r ✭✐✐✐✮ ✳✳✳ q ❙✐❧♦❣✐s♠♦ ❉✐s❥✉♥t✐✈♦ ✭✈✮ q → u ✭❞✮ q ✭✐✈✮ ✳✳✳ u ▼♦❞✉s P♦♥❡♥s ✺ ❉❡ ♦♥❞❡ s❡ ❝♦♥❝❧✉✐ q✉❡ ♦ ♠♦t♦r✐st❛ ♠❛t♦✉ ▲♦r❞ ❈❤❛r❧❡s✳ ✼✳ ❈♦♥str✉❛ ❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡ ♣❛r❛ ❛ s❡❣✉✐♥t❡ ♣r♦♣♦s✐çã♦✿ E = (p⊕ q) ∧ (p⊕ ¬q) ❘❡s♣♦st❛✿ p q (p⊕ q) (p⊕ ¬q) E ❱ ❱ ❋ ❱ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❋ ✽✳ ❈♦♥str✉❛ ❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡ ♣❛r❛ ❛ s❡❣✉✐♥t❡ ♣r♦♣♦s✐çã♦✿ E = (¬p↔ ¬q)→ (p→ ¬r) ❘❡s♣♦st❛✿ p q r ¬p ¬q ¬r (¬p ↔ ¬q) (p → ¬r) E ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❋ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❱ ❱ ❱ ❱ ❱ ✾✳ ❙❡❥❛ ❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡ ❞♦ ♦♣❡r❛❞♦r ⊙✿ p q p ⊙ q ❱ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❋ ❋ ❱ ✭❛✮ ❖ ♦♣❡r❛❞♦r ⊙ s❡❣✉❡ ❛ ❧❡✐ ❞❛ ❛ss♦❝✐❛t✐✈✐❞❛❞❡ ❝♦♠ ♦ ♦♣❡r❛❞♦r ∧✱ ✐✳❡✳✱ (x ⊙ y) ∧ z ? ≡ x ⊙ (y ∧ z). ❘❡s♣♦st❛✿ x y z (x ⊙ y) ∧ z x ⊙ (y ∧ z) ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ❋ ❋ ❱ ❱ ❱ ❋ ❋ ❋ ❋ ❱ ❈♦♠♦ ❛s ❞✉❛s ❝♦❧✉♥❛s ❞❛ ❞✐r❡✐t❛ ♥ã♦ sã♦ ✐❞ê♥t✐❝❛s✱ ♦ ♦♣❡r❛❞♦r ⊙ ♥ã♦ s❡❣✉❡ ❛ ❧❡✐ ❞❛ ❛ss♦❝✐❛t✐✈✐❞❛❞❡ ❝♦♠ ♦ ♦♣❡r❛❞♦r ∧✳ ✭❜✮ ❖ ♦♣❡r❛❞♦r ⊙ s❡❣✉❡ ❛ ❧❡✐ ❞❛ ❞✐str✐❜✉t✐✈✐❞❛❞❡ ❝♦♠ ♦ ♦♣❡r❛❞♦r ∧✱ ✐✳❡✳✱ x ⊙ (y ∧ z) ? ≡ (x ⊙ y) ∧(x ⊙ z). ❘❡s♣♦st❛✿ ✻ x y z x ⊙ (y ∧ z) (x ⊙ y) ∧ (x ⊙ z) ❱ ❱ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❱ ❋ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❋ ❋ ❋ ❱ ❱ ❈♦♠♦ ❛s ❞✉❛s ❝♦❧✉♥❛s ❞❛ ❞✐r❡✐t❛ ♥ã♦ sã♦ ✐❞ê♥t✐❝❛s✱ ♦ ♦♣❡r❛❞♦r ⊙ ♥ã♦ s❡❣✉❡ ❛ ❧❡✐ ❞❛ ❞✐str✐❜✉t✐✈✐❞❛❞❡ ❝♦♠ ♦ ♦♣❡r❛❞♦r ∧✳ ✶✵✳ ▼♦str❡ ❛ ❡q✉✐✈❛❧ê♥❝✐❛ ❧ó❣✐❝❛ ❞❛ s❡❣✉✐♥t❡ ♣r♦♣♦s✐çã♦ ✉s❛♥❞♦ ❛♣❡♥❛s ❛s ❧❡✐s ❞❛ ❧ó❣✐❝❛✿ (p→ r) ∨ (q → r) ≡ (p ∧ q)→ r ❘❡s♣♦st❛✿ (p→ r) ∨ (q → r) ≡ (p ∧ q)→ r (¬p ∨ r) ∨ (¬q ∨ r) ≡ ¬p ∨ ¬q ∨ r ≡ (¬p ∨ ¬q) ∨ r ≡ ¬(¬p ∨ ¬q)→ r ≡ (p ∧ q)→ r ≡ ✶✶✳ ▼♦str❡ s❡ ♦s s❡❣✉✐♥t❡s r❡q✉✐s✐t♦s sã♦ ❝♦♥s✐st❡♥t❡s ♦✉ ♥ã♦✳ ❈❛s♦ s❡❥❛♠✱ ♣❛r❛ q✉❡ ✈❛❧♦r❡s ❡ss❡s r❡q✉✐s✐t♦s sã♦ ❝♦♥s✐st❡♥t❡s✳ ❙❡ ♦ s✐st❡♠❛ ❞❡ ❛rq✉✐✈♦s ♥ã♦ ❡stá tr❛✈❛❞♦✱ ❡♥tã♦ ♥♦✈❛s ♠❡♥s❛❣❡♥s s❡rã♦ ❡♥✜❧❡✐r❛❞❛s✳ ❙❡ ♦ s✐st❡♠❛ ❞❡ ❛rq✉✐✈♦s ♥ã♦ ❡stá tr❛✈❛❞♦✱ ❡♥tã♦ ♦ s✐st❡♠❛ ❡stá ❢✉♥❝✐♦♥❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡ ❡ ✈✐❝❡✲✈❡rs❛✳ ❙❡ ♥♦✈❛s ♠❡♥s❛❣❡♥s ♥ã♦ sã♦ ❡♥✜❧❡✐r❛❞❛s✱ ❡♥tã♦ ❡❧❛s s❡rã♦ ❡♥✈✐❛❞❛s ♣❛r❛ ♦ ❜✉✛❡r ❞❡ ♠❡♥s❛❣❡♥s✳ ❙❡ ♦ s✐st❡♠❛ ❞❡ ❛rq✉✐✈♦s ♥ã♦ ❡stá tr❛✈❛❞♦✱ ❡♥tã♦ ♥♦✈❛s ♠❡♥s❛❣❡♥s s❡rã♦ ❡♥✈✐❛❞❛s ♣❛r❛ ♦ ❜✉✛❡r ❞❡ ♠❡♥s❛❣❡♥s✳ ◆♦✈❛s ♠❡♥s❛❣❡♥s ♥ã♦ s❡rã♦ ❡♥✈✐❛❞❛s ♣❛r❛ ♦ ❜✉✛❡r ❞❡ ♠❡♥s❛❣❡♥s✳ ❘❡s♣♦st❛✿ ❙❡❥❛♠ ♦s s❡❣✉✐♥t❡s ❛r❣✉♠❡♥t♦s✿ p = ❖ s✐st❡♠❛ ❞❡ ❛rq✉✐✈♦s ♥ã♦ ❡stá tr❛✈❛❞♦✳ q = ◆♦✈❛s ♠❡♥s❛❣❡♥s s❡rã♦ ❡♥✜❧❡✐r❛❞❛s✳ r = ❖ s✐st❡♠❛ ❡stá ❢✉♥❝✐♦♥❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡✳ s = ▼❡♥s❛❣❡♥s s❡rã♦ ❡♥✈✐❛❞❛s ♣❛r❛ ♦ ❜✉✛❡r ❞❡ ♠❡♥s❛❣❡♥s✳ ❚r❛❞✉çã♦ ❞♦s ❢❛t♦s ♣❛r❛ ❛s ♣r♦♣♦s✐çõ❡s✿ ✭❛✮ p→ q ✭❜✮ p→ r ✭❝✮ r → p ✭❞✮ ¬q → s ✭❡✮ p→ s ✭❢✮ ¬s ❉❡❞✉çõ❡s✿ ✭✐✮ ¬q → s ✭❞✮ ✼ ¬s ✭❢✮ ✳ ✳ ✳ q ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✐✮ p → s ✭❡✮ ¬s ✭❢✮ ✳ ✳ ✳ ¬p ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✐✐✮ r → p ✭❝✮ ¬p ✭✐✐✮ ✳ ✳ ✳ ¬r ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✈✮ p → r ✭❜✮ ¬r ✭✐✐✐✮ ✳ ✳ ✳ ¬p ▼♦❞✉s ❚♦❧❧❡♥s P❡❧❛s ❞❡❞✉çõ❡s ❛❝✐♠❛ t❡♠♦s q✉❡ ♦s r❡q✉✐s✐t♦s sã♦ ❝♦♥s✐st❡♥t❡s ♣❛r❛ ♦s ✈❛❧♦r❡s✿ ¬p = V ✿ ❖ s✐st❡♠❛ ❞❡ ❛rq✉✐✈♦s ❡stá tr❛✈❛❞♦✳ q = V ✿ ◆♦✈❛s ♠❡♥s❛❣❡♥s s❡rã♦ ❡♥✜❧❡✐r❛❞❛s✳ ¬r = V ✿ ❖ s✐st❡♠❛ ♥ã♦ ❡stá ❢✉♥❝✐♦♥❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡✳ ¬s = V ✿ ▼❡♥s❛❣❡♥s ♥ã♦ s❡rã♦ ❡♥✈✐❛❞❛s ♣❛r❛ ♦ ❜✉✛❡r ❞❡ ♠❡♥s❛❣❡♥s✳ ✶✷✳ ▼♦str❡ s❡ ♦ s❡❣✉✐♥t❡ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞♦ ♦✉ ♥ã♦✿ p ∧ ¬q → r p ∨ q q → p ✳✳✳ r ❘❡s♣♦st❛✿ ❱❛r✐á✈❡✐s ❆✉① Pr❡♠✐ss❛s ❈♦♥❝❧✉sã♦ p q r p ∧ ¬q p ∧ ¬q → r p ∨ q q → p r ✶✳ → ❱ ❱ ❱ ❋ ❱ ❱ ❱ ❱ ✷✳ → ❱ ❱ ❋ ❋ ❱ ❱ ❱ ❋ ✸✳ → ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❱ ✹✳ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ✺✳ ❋ ❱ ❱ ❋ ❱ ❱ ❋ ✻✳ ❋ ❱ ❋ ❋ ❱ ❱ ❋ ✼✳ ❋ ❋ ❱ ❋ ❱ ❋ ❱ ✽✳ ❋ ❋ ❋ ❋ ❱ ❋ ❱ ➜ ❆ ❝♦♥❝❧✉sã♦ é ✈❡r❞❛❞❡✐r❛ ♣❛r❛ ❛s ❧✐♥❤❛s ✶ ❡ ✸ ❡ ❢❛❧s❛ ♣❛r❛ ❛ ❧✐♥❤❛ ✷✳ ❖✉ s❡❥❛✱ ❛ ❝♦♥❝❧✉sã♦ ♥ã♦ é ✈❡r❞❛❞❡✐r❛ ♣❛r❛ t♦❞❛s ❛s ❧✐♥❤❛s ❝rít✐❝❛s✳ ▲♦❣♦✱ ♦ ❛r❣✉♠❡♥t♦ é ✐♥✈á❧✐❞♦✳ ✶✸✳ ▼♦str❡ s❡ ♦ s❡❣✉✐♥t❡ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞♦ ♦✉ ♥ã♦ ✉s❛♥❞♦ ❛s ❢♦r♠❛s ✈á❧✐❞❛s ❞❡ ❛r❣✉♠❡♥t♦s✳ ❊♠ ❝❛❞❛ ♣❛ss♦✱ ✐❞❡♥t✐✜q✉❡ ❛ r❛③ã♦ ♣❛r❛ s❡ ♦❜t❡r ❛ ❝♦♥❝❧✉sã♦✿ ✭❛✮ p→ q ✭❜✮ r ∨ s ✭❝✮ ¬s→ ¬t ✭❞✮ ¬q ∨ s ✭❡✮ ¬s ✭❢✮ ¬p ∧ r → u ✭❣✮ w ∨ t ✭❤✮ ✳✳✳ u ∧ w ✽ ❘❡s♣♦st❛✿ ✭✐✮ r ∨ s ✭❜✮ ¬s ✭❡✮ ✳✳✳ r ❙✐❧♦❣✐s♠♦ ❞✐s❥✉♥t✐✈♦ ✭✐✐✮ ¬q ∨ s ✭❞✮ ¬s ✭❡✮ ✳✳✳ ¬q ❙✐❧♦❣✐s♠♦ ❞✐s❥✉♥t✐✈♦ ✭✐✐✐✮ p→ q ✭❛✮ ¬q ✭✐✐✮ ✳✳✳ ¬p ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✈✮ ¬p ∧ r → u ✭❢✮ ¬p ∧ r ❆❞✐çã♦ ❝♦♥❥✉♥t✐✈❛ ❞❡ ✭✐✐✐✮ ❡ ✭✐✮ ✳✳✳ u ▼♦❞✉s P♦♥❡♥s ✭✈✮ ¬s→ ¬t ✭❝✮ ¬s ✭❡✮ ✳✳✳ ¬t ▼♦❞✉s P♦♥❡♥s ✭✈✐✮ w ∨ t ✭❣✮ ¬t ✭✈✮ ✳✳✳ w ❙✐❧♦❣✐s♠♦ ❞✐s❥✉♥t✐✈♦ ✭✈✐✐✮ u ✭✐✈✮ w ✭✈✐✮ ✳✳✳ u ∧ w ❆❞✐çã♦ ❝♦♥❥✉♥t✐✈❛ ➜ ❖ ❛r❣✉♠❡♥t♦ é ✈á❧✐❞♦✳ ✶✹✳ ❙❡❥❛♠ ❞✉❛s ✈❛r✐á✈❡✐s ❧ó❣✐❝❛s x ❡ y✱ ♦✉ s❡❥❛ ✈❛r✐á✈❡✐s q✉❡ ♣♦❞❡♠ ❛ss✉♠✐r ♦ ✈❛❧♦r ✈❡r❞❛❞❡✐r♦ ✭V ✮ ♦✉ ❢❛❧s♦ ✭F ✮✳ ❙❡❥❛ ← ♦ ❝♦♠❛♥❞♦ ❞❡ ❛tr✐❜✉✐çã♦ ❡①✐st❡♥t❡ ❡♠ ❧✐♥❣✉❛❣❡♥s ❞❡ ♣r♦❣r❛♠❛çã♦ ❝♦♠♦ ❈ ❡ ⊙ ♦ ♦♣❡r❛❞♦r ❞❡✜♥✐❞♦ ♥♦ ❡①❡r❝í❝✐♦ ✾✳ ◗✉❛❧ é ♦ ✈❛❧♦r ❞❡ss❛s ✈❛r✐á✈❡✐s ❛♦ ✜♥❛❧ ❞❛ ❡①❡❝✉çã♦ s❡q✉❡♥❝✐❛❧ ❞♦s três ❝♦♠❛♥❞♦s ❛❜❛✐①♦✳ ❆♣r❡s❡♥t❡ ❛ s✉❛ r❡s♣♦st❛ ✐♥❞❡♣❡♥❞❡♥t❡ ❞♦s ✈❛❧♦r❡s ✐♥✐❝✐❛✐s ❞❡ x ❡ y✳ x← ¬(x⊙ y) y ← ¬(x⊙ y) x← ¬(x⊙ y) ❘❡s♣♦st❛✿ ❘❡❡s❝r❡✈❡♥❞♦ ♦s ❝♦♠❛♥❞♦s ❛❝✐♠❛ ❝♦♠ ♦ ♦♣❡r❛❞♦r ✏♦✉ ❡①❝❧✉s✐✈♦✑ t❡♠♦s ✭✈❡❥❛ ❡①❡r❝í❝✐♦ ✾✮✿ x← (x⊕ y) y ← (x⊕ y) x← (x⊕ y) ❊①❡❝✉t❛♥❞♦ ♦s ❝♦♠❛♥❞♦s ❡ ❧❡♠❜r❛♥❞♦ q✉❡ ♦ ♦♣❡r❛❞♦r ✏♦✉ ❡①❝❧✉s✐✈♦✑ s❡❣✉❡ ❛ ❧❡✐ ❞❛ ❛ss♦❝✐❛t✐✈✐❞❛❞❡ ❡ q✉❡ 0 é ♦ ❡❧❡♠❡♥t♦ ♥❡✉tr♦✱ t❡♠♦s✿ x← (x⊕ y) ✭✶✮ y ← (x⊕ y) ≡ ((x⊕ y)⊕ y) ≡ (x⊕ (y ⊕ y)) ≡ (x⊕ 0) ≡ x ✭✷✮ x← (x⊕ y) ≡ ((x⊕ y)⊕ y) ≡ ((x⊕ y)⊕ x) ≡ ((x⊕ x)⊕ y) ≡ (0⊕ y) ≡ y ✭✸✮ ✾ ◆♦ ❝♦♠❛♥❞♦ ✭✶✮✱ ❛ ✈❛r✐á✈❡❧ x r❡❝❡❜❡ ♦ r❡s✉❧t❛❞♦ ❞❡ x⊕ y✳ ◆♦ ❝♦♠❛♥❞♦ ✭✷✮✱ ❛ ✈❛r✐á✈❡❧ y r❡❝❡❜❡ ♦ r❡s✉❧t❛❞♦ ❞❛ ♦♣❡r❛çã♦ ❞♦ ✏♦✉ ❡①❝❧✉s✐✈♦✑ ❡♥tr❡ ❛ ✈❛r✐á✈❡❧ x✱ q✉❡ ❝♦♥té♠ ♦ r❡s✉❧t❛❞♦ ❞❡ x⊕y✱ ❡ ❛ ✈❛r✐á✈❡❧ y✳ ❖ r❡s✉❧t❛❞♦ ❞❡ss❛ ♦♣❡r❛çã♦ é x✳ ◆♦ ❝♦♠❛♥❞♦ ✭✸✮✱ ❛ ✈❛r✐á✈❡❧ x r❡❝❡❜❡ ♦ r❡s✉❧t❛❞♦ ❞❛ ♦♣❡r❛çã♦ ❞♦ ✏♦✉ ❡①❝❧✉s✐✈♦✑ ❡♥tr❡ ❛ ✈❛r✐á✈❡❧ x✱ q✉❡ ❝♦♥té♠ ♦ r❡s✉❧t❛❞♦ ❞❡ x⊕ y✱ ❡ ❛ ✈❛r✐á✈❡❧ y✱ ❝✉❥♦ ✈❛❧♦r é x✳ ❖ r❡s✉❧t❛❞♦ ❞❡ss❛ ♦♣❡r❛çã♦ é y✳ ❖✉ s❡❥❛✱ ❛♣ós ❛ ❡①❡❝✉çã♦ ❞❡ss❡s três ❝♦♠❛♥❞♦s ❛ ✈❛r✐á✈❡❧ x t❡♠ ♦ ✈❛❧♦r ✐♥✐❝✐❛❧ ❞❡ y ❡ ❛ ✈❛r✐á✈❡❧ y t❡♠ ♦ ✈❛❧♦r ✐♥✐❝✐❛❧ ❞❡ x✳ ❖ t❡①t♦✱ ❛ s❡❣✉✐r✱ ❢♦✐ r❡t✐r❛❞♦ ❞♦ ❧✐✈r♦ t❡①t♦✱ ♣á❣✐♥❛ ✶✾✿ ✏▲ó❣✐❝❛s ❋✉③③② sã♦ ✉t✐❧✐③❛❞❛s ❡♠ ✐♥t❡❧✐❣ê♥❝✐❛ ❛rt✐✜❝✐❛❧✳ ◆❛ ❧ó❣✐❝❛ ❢✉③③②✱ ❛ ♣r♦♣♦s✐çã♦ t❡♠ ✉♠ ✈❛❧♦r✲✈❡r❞❛❞❡ q✉❡ é ✉♠ ♥ú♠❡r♦ ❡♥tr❡ ✵ ❡ ✶ ✐♥❝❧✉s✐✈❡✳ ❯♠❛ ♣r♦♣♦s✐çã♦ ❝♦♠ ✈❛❧♦r✲✈❡r❞❛❞❡ ✵ é ❢❛❧s❛ ❡ ✉♠❛ ❝♦♠ ✈❛❧♦r✲✈❡r❞❛❞❡ ✶ é ✈❡r❞❛❞❡✐r❛✳ ❱❛❧♦r❡s ❡♥tr❡ ✵ ❡ ✶ ✐♥❞✐❝❛♠ ✈❛r✐❛♥t❡s ❞❡ ❣r❛✉ ❞❡ ✈❡r❞❛❞❡✳ P♦r ❡①❡♠♣❧♦✱ ♦ ✈❛❧♦r✲✈❡r❞❛❞❡ ✵✱✽ ♣♦❞❡ s❡r ✐♥❞✐❝❛❞♦ ♣❛r❛ ✉♠❛ ♣r♦♣♦s✐çã♦ ✧❋r❡❞ é ❢❡❧✐③✧✱ ♣♦rq✉❡ ❡❧❡ é ❢❡❧✐③ ♥❛ ♠❛✐♦r ♣❛rt❡ ❞♦ t❡♠♣♦❀ ❡ ♦ ✈❛❧♦r✲✈❡r❞❛❞❡ ✵✱✹ ♣♦❞❡ s❡r ✐♥❞✐❝❛❞♦ ♣❛r❛ ❛ ♣r♦♣♦s✐çã♦ ✧❏♦❤♥ é ❢❡❧✐③✧✱ ♣♦rq✉❡ ❡❧❡ é ❢❡❧✐③ ♠❡♥♦s q✉❡ ❛ ♠❡t❛❞❡ ❞♦ t❡♠♣♦✑✳ ✶✺✳ ❖ ✈❛❧♦r✲✈❡r❞❛❞❡ ❞❛ ♥❡❣❛çã♦ ❞❡ ✉♠❛ ♣r♦♣♦s✐çã♦ ❡♠ ❧ó❣✐❝❛ ❢✉③③② é ✶ ♠❡♥♦s ♦ ✈❛❧♦r✲✈❡r❞❛❞❡ ❞❛ ♣r♦♣♦s✐çã♦✳ ◗✉❛✐s sã♦ ♦s ✈❛❧♦r❡s✲✈❡r❞❛❞❡ ❞❛s ♣r♦♣♦s✐çõ❡s ✧❋r❡❞ ♥ã♦ é ❢❡❧✐③✧ ❡ ✧❏♦❤♥ ♥ã♦ é ❢❡❧✐③✧❄ ❘❡s♣♦st❛✿ pf = 0, 8✿ ✧❋r❡❞ é ❢❡❧✐③✧❀ pj = 0, 4✿ ✧❏♦❤♥ é ❢❡❧✐③✧✳ ¬pf = 1− pf = 1− 0, 8 = 0, 2✿ ✧❋r❡❞ ♥ã♦ é ❢❡❧✐③✧❀ ¬pj = 1− pj = 1− 0, 4 = 0, 6✿ ✧❏♦❤♥ ♥ã♦ é ❢❡❧✐③✧❀ ✶✻✳ ❖ ✈❛❧♦r✲✈❡r❞❛❞❡ ❞❛ ❞✐s❥✉♥çã♦ ❞❡ ❞✉❛s ♣r♦♣♦s✐çõ❡s ❡♠ ❧ó❣✐❝❛ ❢✉③③② é ♦ ♠á①✐♠♦ ❞♦s ✈❛❧♦r❡s✲✈❡r❞❛❞❡ ❞❡ ❞✉❛s ♣r♦♣♦s✐çõ❡s✳ ◗✉❛✐s sã♦ ♦s ✈❛❧♦r❡s✲✈❡r❞❛❞❡ ❞❛s ♣r♦♣♦s✐çõ❡s ✧❋r❡❞ é ❢❡❧✐③ ♦✉ ❏♦❤♥ é ❢❡❧✐③✧ ❡ ✧❋r❡❞ ♥ã♦ é ❢❡❧✐③ ♦✉ ❏♦❤♥ ♥ã♦ é ❢❡❧✐③✧❄ ❘❡s♣♦st❛✿ ❙❡❥❛♠ p ❡ q ✈❛r✐á✈❡✐s ❞❛ ▲ó❣✐❝❛ ❋✉③③②✳ ❆ ❞✐s❥✉♥çã♦ p ∨ q = max(p ; q)✳ ✭❛✮ ✧❋r❡❞ é ❢❡❧✐③ ♦✉ ❏♦❤♥ é ❢❡❧✐③✧✳ pf ∨ pj = max(0, 8; 0, 4) = 0, 8. ✭❜✮ ✧❋r❡❞ ♥ã♦ é ❢❡❧✐③ ♦✉ ❏♦❤♥ ♥ã♦ é ❢❡❧✐③✧ ¬pf ∨ ¬pj = max(0, 2; 0, 6) = 0, 6. ✶✼✳ ❈❛❞❛ ❤❛❜✐t❛♥t❡ ❞❡ ✉♠❛ ✈✐❧❛ ❧♦♥❣í♥q✉❛ s❡♠♣r❡ ❞✐③ ❛ ✈❡r❞❛❞❡ ♦✉ s❡♠♣r❡ ♠❡♥t❡✳ ❯♠ ❤❛❜✐t❛♥t❡ ❞❡❧❛ ❞❛rá ❛♣❡♥❛s ❝♦♠♦ r❡s♣♦st❛ ✉♠ s✐♠ ♦✉ ✉♠ ♥ã♦ ♣❛r❛ ❛ ♣❡r❣✉♥t❛ q✉❡ ✉♠ t✉r✐st❛ ✜③❡r✳ ❙✉♣♦♥❤❛ q✉❡ ✈♦❝ê s❡❥❛ ✉♠ t✉r✐st❛ q✉❡ ✈✐s✐t❛ ❡ss❛ ár❡❛ ❡ q✉❡ ❝❤❡❣✉❡ ❛ ✉♠❛ ❜✐❢✉r❝❛çã♦ ♥❛ ❡str❛❞❛✳ ❯♠ ❧❛❞♦ ❧❡✈❛ ❛té às r✉í♥❛s q✉❡ ✈♦❝ê q✉❡r ✈✐s✐t❛r❀ ♦ ♦✉tr♦✱ às ♣r♦❢✉♥❞❡③❛s ❞❡ ✉♠❛ ✢♦r❡st❛✳ ❯♠ ❤❛❜✐t❛♥t❡ ❞❡ss❛ ✈✐❧❛ ❡stá ♣❛r❛❞♦ ♥❡ss❛ ❜✐❢✉r❝❛çã♦✳ ◗✉❡ ♣❡r❣✉♥t❛ ✈♦❝ê ♣♦❞❡ ❢❛③❡r ❛♦ ❤❛❜✐t❛♥t❡ ♣❛r❛ ❞❡t❡r♠✐♥❛r q✉❛❧ ❧❛❞♦ s❡❣✉✐r❄ ❘❡s♣♦st❛✿ ❙❡ ❢♦r ♣❡r❣✉♥t❛❞♦ s✐♠♣❧❡s♠❡♥t❡ q✉❛❧ ❡str❛❞❛ ❧❡✈❛ às r✉í♥❛s ❡ ♦ t✉r✐st❛ ♥ã♦ s♦✉❜❡r s❡ é ✉♠ ❤❛❜✐t❛♥t❡ q✉❡ ❢❛❧❛ ❛ ✈❡r❞❛❞❡ ♦✉ ♠❡♥t❡✱ ❡♥tã♦ ♥ã♦ é ♣♦ssí✈❡❧ ❞❡t❡r♠✐♥❛r s❡ ❛ r❡s♣♦st❛ é ❝♦rr❡t❛ ♦✉ ♥ã♦✳ ❆ ♣❡r❣✉♥t❛ ♥ã♦ ♣♦❞❡ ❞❡♣❡♥❞❡r ❞♦ t✐♣♦ ❞❡ ❤❛❜✐t❛♥t❡ ❡✱ ♣❛r❛ ✐ss♦✱ é ♥❡❝❡ssár✐♦ ❢♦r♠✉❧❛r ✉♠❛ ♣❡r❣✉♥t❛ q✉❡ ❡♥✈♦❧✈❛ ❞✉❛s q✉❡stõ❡s✳ ❆ss✐♠✱ ❛♦ ✐♥✈és ❞❡ ♣❡r❣✉♥t❛r ✏❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ❧❡✈❛ às r✉í♥❛s❄✑ ✭♣❡r❣✉♥t❛ P✶✮✱ q✉❡ ♥ã♦ r❡s♦❧✈❡ ♦ ♣r♦❜❧❡♠❛✱ ❞❡✈❡✲s❡ ♣❡r❣✉♥t❛r ❛❧❣♦ s✐♠✐❧❛r ❛ ✏s❡ ❡✉ ❢♦ss❡ ❧❤❡ ♣❡r❣✉♥t❛r s❡ ❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ♠❡ ❧❡✈❛ às r✉í♥❛s✱ ✈♦❝ê r❡s♣♦♥❞❡r✐❛ s✐♠❄✑ ✭♣❡r❣✉♥t❛ P✷✮✳ ◆❛t✉r❛❧♠❡♥t❡ ❛ ♠❡s♠❛ ❡str❛té❣✐❛ ♣♦❞❡ s❡r ❢❡✐t❛ ♣❛r❛ ❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❡sq✉❡r❞❛✳ ❱❡❥❛ q✉❡ ❛ ♣❡r❣✉♥t❛ P✷ ♣♦❞❡ s❡r ✈✐st❛ ❝♦♠♦✿ ✏s❡ ❡✉ ❢♦ss❡ ❧❤❡ ♣❡r❣✉♥t❛r s❡ P✶✱ ✈♦❝ê r❡s♣♦♥❞❡r✐❛ s✐♠❄✑✱ ♦ q✉❡ ❝❧❛r❛♠❡♥t❡ ♠♦str❛ q✉❡ ❛ ♣❡r❣✉♥t❛ P✷ tr❛t❛ ❞❡ ❞✉❛s q✉❡stõ❡s✳ ❖ ❤❛❜✐t❛♥t❡ q✉❡ ❢❛❧❛ ❛ ✈❡r❞❛❞❡ r❡s♣♦♥❞❡ ❝♦rr❡t❛♠❡♥t❡✳ ❖ ❤❛❜✐t❛♥t❡ q✉❡ ❢❛❧❛ ♠❡♥t✐r❛ ❞❡✈❡ ✏♠❡♥t✐r ❞✉❛s ✈❡③❡s✑ ♥♦ s❡♥t✐❞♦ q✉❡ s❡ ❛ ♣❡r❣✉♥t❛ ❢♦ss❡ s✐♠♣❧❡s♠❡♥t❡ ✏❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ❧❡✈❛ às r✉í♥❛s❄✑✱ ✐st♦ é✱ P✶✱ ❡❧❡ t❡r✐❛ q✉❡ ♠❡♥t✐r✳ ◆♦ ❡♥t❛♥t♦✱ ❝♦♠♦ ❤á ✉♠❛ s❡❣✉♥❞❛ q✉❡stã♦ ❡♥✈♦❧✈✐❞❛ ✏s❡ ❡✉ ❢♦ss❡ ❧❤❡ ♣❡r❣✉♥t❛r s❡ P✶✱ ✈♦❝ê r❡s♣♦♥❞❡r✐❛ s✐♠❄✑ ❡♥tã♦ ❡ss❡ ❤❛❜✐t❛♥t❡ ❞❡✈❡ ♠❡♥t✐r ♥♦✈❛♠❡♥t❡✳ ❊ss❡ r❛❝✐♦❝í♥✐♦ ❡stá r❡♣r❡s❡♥t❛❞♦ ♥❛ t❛❜❡❧❛ ❛❜❛✐①♦✳ ✶✵ P✶✿ ❆ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ❧❡✈❛ às r✉í♥❛s❄ P✷✿ ❙❡ ❡✉ ❢♦ss❡ ❧❤❡ ♣❡r❣✉♥t❛r s❡ ❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ♠❡ ❧❡✈❛ às r✉í♥❛s✱ ✈♦❝ê r❡s♣♦♥❞❡r✐❛ s✐♠❄ ❚✐♣♦ ❞❡ ❤❛❜✐t❛♥t❡ ❇✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ❧❡✈❛ às r✉í♥❛s❄ P✶ P✷ ❋❛❧❛ ✈❡r❞❛❞❡ ❙✐♠ ❙✐♠ ❙✐♠ ◆ã♦ ◆ã♦ ◆ã♦ ❋❛❧❛ ♠❡♥t✐r❛ ❙✐♠ ◆ã♦ ❙✐♠ ◆ã♦ ❙✐♠ ◆ã♦ ❙❡ ♦ ❤❛❜✐t❛♥t❡ s❡♠♣r❡ ❢❛❧❛ ❛ ✈❡r❞❛❞❡✱ ❡❧❡ ❞✐rá ❛♦ t✉r✐st❛ s❡ ❞❡✈❡ s❡❣✉✐r♣❡❧❛ ❜✐❢✉r❝❛çã♦ ❞❛ ❞✐r❡✐t❛ ♦✉ ❡sq✉❡r❞❛✳ ❙❡ ♦ ❤❛❜✐t❛♥t❡ s❡♠♣r❡ ❢❛❧❛ ♠❡♥t✐r❛✱ ❛♦ r❡s♣♦♥❞❡r ❛ P✷ ❡❧❡ s❛❜❡ q✉❡ ♠❡♥t✐✉ ❛♦ r❡s♣♦♥❞❡r P✶ ✭♣❛rt❡ ❞❡ss❛ ♣❡r❣✉♥t❛✮✳ ◆♦ ❡♥t❛♥t♦✱ ❡❧❡ ♠❡♥t❡ ♥♦✈❛♠❡♥t❡ ❡✱ ♥♦ ✜♥❛❧✱ ❡❧❡ r❡s♣♦♥❞❡ ❝♦rr❡t❛♠❡♥t❡ ❛ ❜✐❢✉r❝❛çã♦ ❛ s❡r s❡❣✉✐❞❛✳ ❆ ❡str❛té❣✐❛ é ✉s❛r ✉♠❛ ❞✉♣❧❛ ♥❡❣❛t✐✈❛✳ ✶✽✳ ❊st❡ s✐st❡♠❛ ❞❡ ❡s♣❡❝✐✜❝❛çõ❡s é ❝♦♥s✐st❡♥t❡❄ ✏❖ s✐st❡♠❛ ❡stá ❡♠ ✉♠ ❡st❛❞♦ ❞❡ ♠✉❧t✐✉s♦ s❡ ❡ s♦♠❡♥t❡ s❡ ❡st✐✈❡r ♦♣❡r❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡✳ ❙❡ ♦ s✐st❡♠❛ ❡stá ♦♣❡r❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡✱ ♦ ♥ú❝❧❡♦ ❞♦ s✐st❡♠❛ ♦♣❡r❛❝✐♦♥❛❧ ✭❦❡r♥❡❧✮ ❡stá ❢✉♥❝✐♦♥❛♥❞♦✳ ❖ ❦❡r♥❡❧ ♥ã♦ ❡stá ❢✉♥❝✐♦♥❛♥❞♦ ♦✉ ♦ s✐st❡♠❛ ❡stá ♥♦ ♠♦❞♦ ❞❡ ✐♥t❡rr✉♣çã♦✳ ❙❡ ♦ s✐st❡♠❛ ♥ã♦ ❡stá ❡♠ ✉♠ ❡st❛❞♦ ❞❡ ♠✉❧t✐✉s♦✱ ❡♥tã♦ ❡stá ❡♠ ✉♠ ♠♦❞♦ ❞❡ ✐♥t❡rr✉♣çã♦✳ ❖ s✐st❡♠❛ ♥ã♦ ❡stá ♥♦ ♠♦❞♦ ❞❡ ✐♥t❡rr✉♣çã♦✳✑ ❘❡s♣♦st❛✿ ❙❡❥❛♠ ♦s s❡❣✉✐♥t❡s ❛r❣✉♠❡♥t♦s✿ p = ❖ s✐st❡♠❛ ❡stá ❡♠ ✉♠ ❡st❛❞♦ ❞❡ ♠✉❧t✐✉s♦✳ q = ❖ s✐st❡♠❛ ❡stá ♦♣❡r❛♥❞♦ ♥♦r♠❛❧♠❡♥t❡✳ r = ❖ ♥ú❝❧❡♦ ❞♦ s✐st❡♠❛ ♦♣❡r❛❝✐♦♥❛❧ ✭❦❡r♥❡❧✮ ❡stá ❢✉♥❝✐♦♥❛♥❞♦✳ s = ❖ s✐st❡♠❛ ❡stá ♥♦ ♠♦❞♦ ❞❡ ✐♥t❡rr✉♣çã♦✳ ❚r❛❞✉çã♦ ❞♦s ❢❛t♦s ♣❛r❛ ❛s ♣r♦♣♦s✐çõ❡s✿ ✭❛✮ p↔ q ≡ (p→ q) ∧ (q → p) ✭❜✮ q → r ✭❝✮ ¬r ∨ s ✭❞✮ ¬p→ s ✭❡✮ ¬s ❉❡❞✉çõ❡s✿ ✭✐✮ ¬r ∨ s ✭❝✮ ¬s ✭❡✮ ✳ ✳ ✳ ¬r ❙✐❧♦❣✐s♠♦ ❉✐s❥✉♥t✐✈♦ ✭✐✐✮ q → r ✭❜✮ ¬r ✭✐✮ ✳ ✳ ✳ ¬q ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✐✐✮ ¬p → s ✭❞✮ ¬s ✭❡✮ ✳ ✳ ✳ p ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✈✮ (p → q) ∧ (q → p) ✭❛✮ ✳ ✳ ✳ p → q ❙✐♠♣❧✐✜❝❛çã♦ ❈♦♥❥✉♥t✐✈❛ ✭✈✮ p → q ✭✐✈✮ ¬q ✭✐✐✮ ✶✶ ✳ ✳ ✳ ¬p ▼♦❞✉s ❚♦❧❧❡♥s ❆s ❝♦♥❝❧✉sõ❡s ✭✐✐✐✮ ❡ ✭✈✮ ❞✐③❡♠ q✉❡ p ❡ ¬p ❞❡✈❡♠ s❡r ✈❡r❞❛❞❡✐r♦s✱ ♦ q✉❡ ❝❧❛r❛♠❡♥t❡ é ✐♥❝♦♥s✐st❡♥t❡✳ ✶✾✳ ❊st❡ s✐st❡♠❛ ❞❡ ❡s♣❡❝✐✜❝❛çõ❡s é ❝♦♥s✐st❡♥t❡❄ ✏❖ r♦t❡❛❞♦r ♣♦❞❡ ❡♥✈✐❛r ♠❡♥s❛❣❡♥s ♣❛r❛ ♦ s✐st❡♠❛ ♣r✐♥❝✐♣❛❧ s♦♠❡♥t❡ s❡ ❡❧❡ tr❛t❛r ✉♠ ♥♦✈♦ ❡s♣❛ç♦ ❞❡ ❡♥❞❡r❡ç♦✳ P❛r❛ ♦ r♦t❡❛❞♦r tr❛t❛r ♦ ♥♦✈♦ ❡s♣❛ç♦ ❞❡ ❡♥❞❡r❡ç♦✱ é ♥❡❝❡ssár✐♦ q✉❡ ❛ ú❧t✐♠❛ ✈❡rsã♦ ❞♦ s♦❢t✇❛r❡ s❡❥❛ ✐♥st❛❧❛❞❛✳ ❖ r♦t❡❛❞♦r ♣♦❞❡ ❡♥✈✐❛r ♠❡♥s❛❣❡♥s ❛♦ s✐st❡♠❛ ♣r✐♥❝✐♣❛❧ s❡ ❛ ú❧t✐♠❛ ✈❡rsã♦ ❞♦ s♦❢t✇❛r❡ ❡st✐✈❡r ✐♥st❛❧❛❞❛✳ ❖ r♦t❡❛❞♦r ♥ã♦ tr❛t❛ ♦ ♥♦✈♦ ❡s♣❛ç♦✳✑ ❘❡s♣♦st❛✿ ❙❡❥❛♠ ♦s s❡❣✉✐♥t❡s ❛r❣✉♠❡♥t♦s✿ p = ❖ r♦t❡❛❞♦r ♣♦❞❡ ❡♥✈✐❛r ♠❡♥s❛❣❡♥s ♣❛r❛ ♦ s✐st❡♠❛ ♣r✐♥❝✐♣❛❧✳ q = ❖ r♦t❡❛❞♦r tr❛t❛ ✉♠ ♥♦✈♦ ❡s♣❛ç♦ ❞❡ ❡♥❞❡r❡ç♦✳ r = ❆ ú❧t✐♠❛ ✈❡rsã♦ ❞♦ s♦❢t✇❛r❡ s❡❥❛ ✐♥st❛❧❛❞❛✳ ❚r❛❞✉çã♦ ❞♦s ❢❛t♦s ♣❛r❛ ❛s ♣r♦♣♦s✐çõ❡s✿ ✭❛✮ p s♦♠❡♥t❡ s❡ q ≡ p→ q ✭❜✮ ♣❛r❛ q é ♥❡❝❡ssár✐♦ r ≡ r é ✉♠❛ ❝♦♥❞✐çã♦ ♥❡❝❡ssár✐❛ ♣❛r❛ q ≡ q → r ✭❝✮ p s❡ r ≡ r → p ≡ ¬p→ ¬r ✭❞✮ ¬q ❉❡❞✉çã♦✿ ✭✐✮ p → q ✭❛✮ ¬q ✭❞✮ ✳ ✳ ✳ ¬p ▼♦❞✉s ❚♦❧❧❡♥s ✭✐✐✮ ¬p → ¬r ✭❝✮ ¬p ✭✐✮ ✳ ✳ ✳ ¬r ▼♦❞✉s P♦♥❡♥s P❡❧❛s ❞❡❞✉çõ❡s ❛❝✐♠❛✱ ❛s três ♣r♦♣♦s✐çõ❡s sã♦ ❢❛❧s❛s✿ ¬q ❞❡ ❛❝♦r❞♦ ❝♦♠ ✭❞✮✱ ¬p ❞❡ ❛❝♦r❞♦ ❝♦♠ ✭✐✮ ❡ ¬r ❞❡ ❛❝♦r❞♦ ❝♦♠ ✭✐✐✮✳ ❙❡ t♦❞❛s três ♣r♦♣♦s✐çõ❡s sã♦ ❢❛❧s❛s✱ ❛s q✉❛tr♦ ❡s♣❡❝✐✜❝❛çõ❡s sã♦ ✈❡r❞❛❞❡✐r❛s ❡ ❡❧❛s sã♦ ❝♦♥s✐st❡♥t❡s✳ ✷✵✳ ❯♠ ❞❡t❡t✐✈❡ ❡♥tr❡✈✐st♦✉ q✉❛tr♦ t❡st❡♠✉♥❤❛s ❞❡ ✉♠ ❝r✐♠❡✳ ❆ ♣❛rt✐r ❞❛s ❤✐stór✐❛s ❞❛s t❡st❡♠✉♥❤❛s✱ ♦ ❞❡t❡t✐✈❡ ❝♦♥❝❧✉✐✉ q✉❡✱ s❡ ♦ ♠♦r❞♦♠♦ ❡stá ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡✱ ❡♥tã♦ ♦ ❝♦③✐♥❤❡✐r♦ t❛♠❜é♠ ❡stá❀ ♦ ❝♦③✐♥❤❡✐r♦ ❡ ♦ ❥❛r❞✐♥❡✐r♦✱ ❛♠❜♦s✱ ♥ã♦ ♣♦❞❡♠ ❡st❛r ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡❀ ♦ ❥❛r❞✐♥❡✐r♦ ❡ ♦ ③❡❧❛❞♦r✱ ❛♠❜♦s✱ ♥ã♦ ❡stã♦ ♠❡♥t✐♥❞♦❀ ❡ s❡ ♦ ③❡❧❛❞♦r ❡stá ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡✱ ❡♥tã♦ ♦ ❝♦③✐♥❤❡✐r♦ ❡stá ♠❡♥t✐♥❞♦✳ P❛r❛ ❝❛❞❛ ✉♠❛ ❞❛s q✉❛tr♦ t❡st❡♠✉♥❤❛s✱ ♦ ❞❡t❡t✐✈❡ ♣♦❞❡ ❞❡t❡r♠✐♥❛r s❡ ❛ ♣❡ss♦❛ ❡stá ♠❡♥t✐♥❞♦ ♦✉ ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡❄ ❘❡s♣♦st❛✿ ❆s q✉❛tr♦ t❡st❡♠✉♥❤❛s ♣♦❞❡♠ s❡r ✐❞❡♥t✐✜❝❛❞❛s ♣❡❧❛s ✈❛r✐á✈❡✐s C ✭❝♦③✐♥❤❡✐r♦✮✱ J ✭❥❛r❞✐♥❡✐r♦✮✱ M ✭♠♦r❞♦♠♦✮ ❡ Z ✭③❡❧❛❞♦r✮✱ q✉❡ s❡rã♦ ✉s❛❞❛s ♣❛r❛ ✐♥❞✐❝❛r q✉❡ ❡stã♦ ❢❛❧❛♥❞♦ ❛ ✈❡r❞❛❞❡✳ ❙❡❥❛♠ ♦s s❡❣✉✐♥t❡s ❛r❣✉♠❡♥t♦s✿ ✭❛✮ M → C ❬s❡ ♦ ♠♦r❞♦♠♦ ❡stá ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡✱ ❡♥tã♦ ♦ ❝♦③✐♥❤❡✐r♦ t❛♠❜é♠ ❡stá❪ ✭❜✮ C ⊕ J ❬♦ ❝♦③✐♥❤❡✐r♦ ❡ ♦ ❥❛r❞✐♥❡✐r♦✱ ❛♠❜♦s✱ ♥ã♦ ♣♦❞❡♠ ❡st❛r ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡❪ ✭❝✮ ¬J ⊕ ¬Z ❬♦ ❝♦③✐♥❤❡✐r♦ ❡ ♦ ❥❛r❞✐♥❡✐r♦✱ ❛♠❜♦s✱ ♥ã♦ ♣♦❞❡♠ ❡st❛r ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡❪ ✭❞✮ Z → ¬C ❬s❡ ♦ ③❡❧❛❞♦r ❡stá ❞✐③❡♥❞♦ ❛ ✈❡r❞❛❞❡✱ ❡♥tã♦ ♦ ❝♦③✐♥❤❡✐r♦ ❡stá ♠❡♥t✐♥❞♦❪ P❡❧♦s q✉❛tr♦ ❛r❣✉♠❡♥t♦s ❛❝✐♠❛✱ ♥ã♦ é ♣♦ssí✈❡❧ ❛♣❧✐❝❛r ✉♠❛ r❡❣r❛ ❞❡ ✐♥❢❡rê♥❝✐❛✳ ❙❡ ✜③❡r♠♦s ✉♠❛ t❛❜❡❧❛ ❞❛ ✈❡r❞❛❞❡✱ ♣♦❞❡♠♦s ✐❞❡♥t✐✜❝❛r ♦ ❝❡♥ár✐♦ ♥♦ q✉❛❧ ❛s q✉❛tr♦ ♣r❡♠✐ss❛s s✉♣♦st❛♠❡♥t❡ sã♦ ✈❡r❞❛❞❡✐r❛s✱ ❝♦♥❢♦r♠❡ ♠♦str❛❞♦ ❛ s❡❣✉✐r✳ ✶✷ ❱❛r✐á✈❡✐s Pr❡♠✐ss❛s C J M Z ✭❛✮ ✭❜✮ ✭❝✮ ✭❞✮ ✶✳ ❱ ❱ ❱ ❱ ❱ ❋ ❋ ❋ ✷✳ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ❱ ✸✳ ❱ ❱ ❋ ❱ ❱ ❋ ❋ ❋ ✹✳ ❱ ❱ ❋ ❋ ❱ ❋ ❱ ❱ ✺✳ ❱ ❋ ❱ ❱ ❱ ❱ ❱ ❋ ✻✳ ❱ ❋ ❱ ❋ ❱ ❱ ❋ ❱ ✼✳ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ❋ ✽✳ ❱ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ✾✳ ❋ ❱ ❱ ❱ ❋ ❱ ❋ ❱ ✶✵✳ ❋ ❱ ❱ ❋ ❋ ❱ ❱ ❱ ✶✶✳ ❋ ❱ ❋ ❱ ❱ ❱ ❋ ❱ ✶✷✳ → ❋ ❱ ❋ ❋ ❱ ❱ ❱ ❱ ✶✸✳ ❋ ❋ ❱ ❱ ❋ ❱ ❱ ❱ ✶✹✳ ❋ ❋ ❱ ❋ ❋ ❋ ❋ ❱ ✶✺✳ ❋ ❋ ❋ ❱ ❱ ❋ ❱ ❱ ✶✻✳ ❋ ❋ ❋ ❋ ❱ ❋ ❋ ❱ ➜ ❆s ♣r❡♠✐ss❛s sã♦ ✈❡r❞❛❞❡✐r❛s ♣❛r❛ ❛ ❧✐♥❤❛ ✶✷✱ ♦✉ s❡❥❛✱ ♦ ❥❛r❞✐♥❡✐r♦ ❢❛❧❛ ❛ ✈❡r❞❛❞❡ ❡ ❛s ♦✉tr❛s t❡st❡♠✉♥❤❛s ♥ã♦✳ ❖ t❡①t♦✱ ❛ s❡❣✉✐r✱ ❢♦✐ r❡t✐r❛❞♦ ❞♦ ❧✐✈r♦ t❡①t♦✱ ♣á❣✐♥❛ ✷✾✿ ✏❖ ❞✉❛❧ ❞❡ ✉♠❛ ♣r♦♣♦s✐çã♦ ❝♦♠♣♦st❛ q✉❡ ❝♦♥té♠ ❛♣❡♥❛s ♦s ♦♣❡r❛❞♦r❡s ❧ó❣✐❝♦s ∨✱ ∧ ❡ ¬ é ❛ ♣r♦♣♦s✐çã♦ ❝♦♠♣♦st❛ ♦❜t✐❞❛ ♣❡❧❛ tr♦❝❛ ❞❡ ❝❛❞❛ ∨ ♣♦r ∧✱ ❝❛❞❛ ∧ ♣♦r ∨✱ ❝❛❞❛ V ♣♦r F ❡ ❝❛❞❛ F ♣♦r V ✳ ❖ ❞✉❛❧ ❞❡ s é r❡♣r❡s❡♥t❛❞♦ ♣♦r s∗✑✳ ✷✶✳ ❊♥❝♦♥tr❡ ♦ ❞✉❛❧ ❞❡ ❝❛❞❛ ✉♠❛ ❞❛s s❡❣✉✐♥t❡s ♣r♦♣♦s✐çõ❡s ❝♦♠♣♦st❛s✿ ✭❛✮ s1 : p ∧ ¬q ∧ ¬r ❘❡s♣♦st❛✿ s∗1 : p ∨ ¬q ∨ ¬r ✭❜✮ s2 : (p ∧ q ∧ r) ∨ s ❘❡s♣♦st❛✿ s∗2 : (p ∨ q ∨ r) ∧ s ✭❝✮ s3 : (p ∨ F ) ∧ (q ∨ V ) ❘❡s♣♦st❛✿ s∗3 : (p ∧ V ) ∨ (q ∧ F ) ✭❞✮ ❆♣r❡s❡♥t❡ ✉♠ ❡①❡♠♣❧♦ ❞❡ ♣r♦♣♦s✐çã♦ ❝♦♠♣♦st❛ ❢♦r♠❛❞❛ ♣♦r ♣❡❧♦ ♠❡♥♦s ❞✉❛s ✈❛r✐á✈❡✐s t❛❧ q✉❡ s ≡ s∗✳ ❘❡s♣♦st❛✿ s4✿ (p ∨ F ) ∧ (q ∨ V ) p ∧ V p s∗4✿ (p ∧ V ) ∨ (q ∧ F ) p ∨ F p ✶✸