companydirectorylist.com  Global Business Directories and Company Directories
Search Business,Company,Industry :


Country Lists
USA Company Directories
Canada Business Lists
Australia Business Directories
France Company Lists
Italy Company Lists
Spain Company Directories
Switzerland Business Lists
Austria Company Directories
Belgium Business Directories
Hong Kong Company Lists
China Business Lists
Taiwan Company Lists
United Arab Emirates Company Directories


Industry Catalogs
USA Industry Directories














  • notation - In Logic is ⇒, →, and ⊃ basically the same symbol . . .
    As for ⇒ ⇒, this has been used as a sequent former in formal sequent calculi; but also seems often to be used (in some places, at any rate) as a metalinguistic symbol (i e not part of a formal object language, but as shorthand in mathematical English) to mean "logically entails" (so something stronger than the material conditional)
  • Why is the selection of logical connectives {¬,∨,∧,⇒,⇔}, in set theory?
    Is not exhaustive either, since there are actually 16 possible compound statements (and corresponding logical connectives) to choose from (Since {¬,∨,∧,⇒,⇔} is already redundant, why not throw in the other 11 connectives, some of which are VERY helpful like "nand" ⊼ , "nor" ⊽ and "exclusive or" ⊻?) Some of the "16 possible compound statements" are in fact trivial cases (and
  • Implication and equivalence arrows, when to use them?
    In my course book we have something called implication arrows ⇒ ⇒ and equivalence arrows ⇔ ⇔ and I have never managed to understand them When do I know which to use and how do I know that I'm correct when I use them?
  • What is the difference between implication symbols:
    16 There is no universally observed difference between the two symbols ⇒ ⇒ tends to be used more often in undergraduate instruction, where the logical symbols are used to explain and elucidate ordinary mathematical arguments -- for example, in real analysis
  • What are these symbols in logic called? - Mathematics Stack Exchange
    Sometimes yes; sometimes ⇒ ⇒ means logical consequence; sometimes ⇒ ⇒ means a meta-linguistic (= mathematical English) "if then" Is ↔ ↔ (a connective between formulas, to create a compound formula, defined in terms of → →) called (material) equivalence?
  • Difference between implies and turnstile symbols (→ and ⊢)
    According to Wikipedia's list of logic symbols: A → B means A → B is false when A is true and B is false but true otherwise A ⊢ B means x ⊢ y means x proves (syntactically entails) y But for me I
  • Simplicify $((A ⇒ B) ⇒ (B ⇒ A)) ⇒( ¬(A∧B) ⇔ ¬(B∨A))$
    Rather than defining ∧ ∧ by using , I would define using ∨ ∨, and get rid of all those arrows Once you have just ¬, ∧ ¬, ∧ and ∨ ∨, simplification is a bit easier than expressions containing only ¬ ¬ and , in my opinion Of course, you could just draw up a truth table; there would only be four rows, after all
  • discrete mathematics - Show that (p ∧ q) → (p ∨ q) is a tautology . . .
    I am having a little trouble understanding proofs without truth tables particularly when it comes to → Here is a problem I am confused with: Show that (p ∧ q) → (p ∨ q) is a tautology The firs




Business Directories,Company Directories
Business Directories,Company Directories copyright ©2005-2012 
disclaimer