BFO 9000 Math Map ❡
Logic ❡
| Symbol |
Unicode |
Meaning |
| ∧ |
U2227 |
wedge / logical AND |
| ∨ |
U2228 |
vee / logical OR |
| ¬ |
notsign / U00AC |
NOT |
| ⇒ |
U21D2 |
implication |
| ⇐ |
U21D0 |
implied by |
| ⇔ |
U21D4 |
equivalence |
| ∀ |
U2200 |
for all |
| ∃ |
U2203 |
there exists |
| ∄ |
U2204 |
there does not exist |
| ⊤ |
U22A4 |
true |
| ⊥ |
U22A5 |
false / bottom |
| ⊢ |
U22A2 |
proves |
| ⊨ |
U22A8 |
models / entails |
Sets ❡
| Symbol |
Unicode |
Meaning |
| ∈ |
elementof |
|
| ∉ |
notelementof |
|
| ∋ |
U220B |
|
| ⊂ |
U2282 |
|
| ⊃ |
U2283 |
|
| ⊆ |
U2286 |
|
| ⊇ |
U2287 |
|
| ∅ |
emptyset |
|
| ∪ |
union |
|
| ∩ |
intersection |
|
| ∖ |
U2216 |
set difference |
Algebra ❡
| Symbol |
Unicode |
| × |
U00D7 |
| ÷ |
division |
| ± |
plusminus |
| ∓ |
U2213 |
| ∙ |
U2219 |
| ∘ |
U2218 |
| √ |
radical |
| ∛ |
U221B |
| ∜ |
U221C |
| ∞ |
infinity |
| ≈ |
approximate |
| ≠ |
notequal |
| ≤ |
lessthanequal |
| ≥ |
greaterthanequal |
Calculus ❡
| Symbol |
Unicode |
| ∂ |
partialderivative |
| ∇ |
U2207 |
| ∫ |
integral |
| ∬ |
U222C |
| ∭ |
U222D |
| ∮ |
U222E |
| ∑ |
U2211 |
| ∏ |
U220F |
Category theory ❡
| Symbol |
Unicode |
| ∘ |
U2218 |
| ↦ |
U21A6 |
| ↣ |
U21A3 |
| ↪ |
U21AA |
| ↠ |
U21A0 |
| ≅ |
U2245 |
| ≃ |
U2243 |
| ≡ |
identical |
| ⊣ |
U22A3 |
| ⊢ |
U22A2 |
| ⊥ |
U22A5 |
Linear algebra ❡
| Symbol |
Unicode |
| · |
periodcentered |
| ⊗ |
U2297 |
| ⊕ |
U2295 |
| ⊙ |
U2299 |
| ⊖ |
U2296 |
| ⊘ |
U2298 |
| ⋅ |
U22C5 |
| ⟨ |
U27E8 |
| ⟩ |
U27E9 |
Some favorites ❡
∀ ∃ ∄
∧ ∨ ¬
⇒ ⇔
⊤ ⊥
∈ ∉ ⊂ ⊆
∩ ∪ ∅
∂ ∇ ∫ ∑ ∏
⊗ ⊕
∘ ↦
≅ ≃ ≡
⟨ ⟩
∞
One nice XKB convention is to group related operators on the same key:
∧ ∨
∩ ∪
⊂ ⊃
⊆ ⊇
≤ ≥
← →
↑ ↓
⇒ ⇔
⊤ ⊥
∈ ∉
That makes it much easier to remember the layout because each key represents a conceptual pair rather than unrelated symbols.