P(x) : x > 3∀x > 4, P (x)
∀x > 2, P (x)
∃x∈E, P (x)x E P (x)
∃x∈E|P(x)
P(x) : x > 3∃x > 2|P(x)∃x < 2|P(x)
E
2 2
E
∃y > 2,∀x > y, P (x)
Q(z) : ∀y > z, ∃x < y |P(x).
∀x∈E, P (x)∀a∈E, P (a)
∃y > 2| ∀x≥y, P (x) ”∃x > 2| ∀x≥x, P (x)
non”∀x∈E, P (x)” = ”∃x∈E, nonP (x)”,
non”∃x∈E, P (x)” = ”∀x∈E, nonP (x)”.
∀x∈E, P (x)∃x∈Ec|P(x)
EcE
∀x > 2, x > 3∃x > 2|x≤3
∃x≤2|x≤3
∃x > a, ∀y < x, y > 4
∀ ∃
∀x∈E, ∃y∈F, P (x, y)∃y∈F, ∀x∈E, P (x, y)
∀y∈E, ∃x∈F, P (y, x)
∀x > 3,∃y > 2, y > x ∃y > 2,∀x > 3, y > x