Words such as 1, "to the full amount" and "to any" are logically called universal quantifiers and recorded as "?" A proposition that contains a full-name quantifier is called a universal proposition.

For any x in m, there is p(x), which is recorded as? X ∈ M. pronounced: For any X belonging to M, p(x) holds.

2. Words such as "you yi" and "at least one" are logically called existential quantifiers and recorded as "?" Propositions containing existential quantifiers are called special propositions.

There is at least one x in m, which makes p(x) hold, and it is recorded as? X∈M .Read: read: There is an x belonging to m, which makes p(x) hold.

Extended data:

Introduction to common mathematical symbols:

1, geometric symbol

⊥ ∥ ∠ ⌒ ⊙ ≡ ≌? △

2. Algebraic symbols

∝ ∧ ∨ ~ ∫ ≠? ≤ ≥ ≈ ∞

3. Operation symbols

Such as plus sign (+), minus sign (-), multiplication sign (× or), division sign (÷ or/), union of two sets (∩), intersection (∩), root sign (√), logarithm (log, lg, ln) and ratio (:).

4. Symbol set

∪ ∩ ∈

5. Special symbols

∑? π(π)

6. Inference symbols

| One |? ⊥? ∽? △? ∠? ∩? ∪? ≠? ≡? ? ≥? ≤? ∈? ←