Field Extension
A Field 
is said to be a field extension of field 
if is a Subfield of . This is denoted 
(note that this Notation conflicts with that of a Quotient Group). The Complex Numbers are a field extension of the Real Numbers, and the Real Numbers are afield extension of the Rational Numbers.
- Flyping Conjecture
- Focus
- Fold Bifurcation
- Fold Catastrophe
- Folding
- Foliation
- Folium
- Folium of Descartes
- Follows
- Fontené Theorems
- Foot
- For All
- Forcing
- Ford Circle
- Ford's Theorem
- Forest
- Fork
- Form
- Formal Logic
- Form (Geometric)
- Formosa Theorem
- Form (Polynomial)
- Formula
- Fortunate Prime
- Forward Difference