User:Philogo/sandbox

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Logic: ¬ ∧ ∨ ∃ ∀ ¬ ∧ ∨ ∃ ∀
&not
Failed to parse (syntax error): &not

<math>\not\equiv</math>: mess about
<math>A\not \models_L X</math>:
implies


↑ or ↑ or | or ↑

↓
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¬
¬
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| rowspan=3 bgcolor=#d0f0d0 align=center|

||material equivalence | rowspan=3|A ⇔ B means A is true if B is true and A is false if B is false. | rowspan=3|x + 5 = y +2  ⇔  x + 3 = y ! rowspan="3" |8660

8596 ! rowspan="3" | &hArr;
&equiv;
&harr;

! rowspan="3" |

|-

1. 1 A ⇔ B
2. 2
3. 3 &hArr;
   &equiv;
   &harr;
4. 4
   \Leftrightarrow
   \equiv
   \leftarrow
5. 5
   
6. 6
7. 7
8. 8 ,
9. 9
10. 10
11. 11 ,
12. 12 ,
13. 13 T B
14. 14 The inference rule called Universal Generalization is characteristic of the predicate calculus. It can be stated as

if , then

Which reads: if φ is a theorem, then "for every x, φ" is a theorem as well.

1. 
2. 
3. 
4. 
5. 

These cannopt be raad at work:- they look tiny & wierd

• {{nor-}} - ↓
• {{nand}} - ↑
• {{cnv}} - ←

these look like boxes:-

• {{cni}} - ⊄
• {{nonimp}} - ⊅

try

• Biconditional (xnor) ( or )
  

( or )