SAT数学运算常用符号介绍

2022-05-25 13:36:41

  Logical Symbols

  A ⇒ B means if A is true then B is also true; if A is false then nothing is said about B.

  → may mean the same as ⇒ (the symbol may also indicate the domain and codomain of a function; see table of mathematical symbols).

  ⊃ may mean the same as ⇒ (the symbol may also mean superset).

  A ⇔ B means A is true if B is true and A is false if B is false.

  The statement ¬A is true if and only if A is false.

  The statement A ∧ B is true if A and B are both true; else it is false.

  The statement A ∨ B is true if A or B (or both) are true; if both are false, the statement is false.

  ∀ x: P(x) means P(x) is true for all x.

  ∃ x: P(x) means there is at least one x such that P(x) is true.

  ∃! x: P(x) means there is exactly one x such that P(x) is true.

  x ⊢ y means y is derived from x.

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