a←β的值 (1)aφβ是-((a→B)→-()→a)的简写 (2)(a4B) =1-(a→6)→-(→a)0 =1-max{1-(a→),1-(→a)?} =min{(a→),(→a)} min max 1-a, B01, max1-B0a1 min max1,a+30)-ao max{1,a+}-B0} =maX{1,Q+60}+min{-a0,-B} max(1, a+Bo-maxa, Bo)α ↔ β (1) α ↔ β ¬((α→β) → ¬(β→α)) . (2) (α ↔ β)σ = 1 − ((α→β) → ¬(β→α))σ = 1 − max{1 − (α→β)σ, 1 − (β→α))σ} = min{(α→β)σ, (β→α)σ} = min{max{1 − ασ, βσ}, max{1 − βσασ}} = min{max{1, ασ + βσ} − ασ, max{1, ασ + βσ} − βσ} = max{1, ασ + βσ} + min{−ασ, −βσ} = max{1, ασ + βσ} − max{ασ, βσ} 8