Synclastic
A surface on which the Gaussian Curvature 
is everywhere Positive. When is everywhere Negative, a surfaceis called Anticlastic. A point at which the Gaussian Curvature is Positive is called an EllipticPoint.
- Euler Differential Equation
- Euler Equation
- Euler Formula
- Euler Four-Square Identity
- Euler Graph
- Eulerian Circuit
- Eulerian Cycle
- Eulerian Integral of the First Kind
- Eulerian Integral of the Second Kind
- Eulerian Number
- Eulerian Trail
- Euler Identity
- Euler Integral
- Euler-Jacobi Pseudoprime
- Euler-Lagrange Derivative
- Euler-Lagrange Differential Equation
- Euler L-Function
- Euler Line
- Euler-Lucas Pseudoprime
- Euler-Maclaurin Integration Formulas
- Euler-Mascheroni Constant
- Euler-Mascheroni Integrals
- Euler Measure
- Euler Number
- Euler Parameters