Name of partial derivatives where the order of differentiation can be reversed. Is there a name given to partial differential equations of the form: $$\frac{\partial{F}}{\partial{x}\partial{y}}=\frac{\partial{F}}{\partial{y}\partial{x}}$$ Not asking for any kind of proof, just specifically wondering if there is a name given to PDE's that satisfy this condition.

I suspect that the equality
$$\frac{\partial{F}}{\partial{x}\partial{y}}=\frac{\partial{F}}{\partial{y}\partial{x}},$$
interpreted as a pde, have no special name because it is not commonly interpreted as a pde.
On the other hand, understood as "a condition on" or "a property of" a certain function $F$, the said equality is usually referred to as


*

*Equality of mixed partial derivatives.

*Symmetry of second derivatives.

*Symmetry of the hessian matrix.

