We can derive fundamental results in calculus, Euclidean geometry, analytic geometry, complex analysis, and differential equations, based on this new definition of division by zero calculus, for example, $\tan (\pi/2) = 0$, $\log 0=0$, $[z^n/n]_{n=0} = \log z$, $[e^{(1/z)}]_{z=0} = 1$.
ミカの第1、第2基本定理とは 正確に次を述べている:
In our previous announcement \cite{fund}, we demonstrated that for a smooth hypersurface $M_0 = \{x \in {\bf R}^n \mid \phi(x) = 0\}$ with $\nabla \phi(x) \neq 0$, the multidimensional division by zero calculus for the quotient $f(x)/\phi(x)$ yields a remarkably simple, coordinate-free gradient invariant formula:
\frac{f(x)}{\phi(x)}\bigg|_{\phi=0} = \frac{\nabla f(x) \cdot \nabla \phi(x)}{|\nabla \phi(x)|^2}. \end{equation} Furthermore, the second-order quotient $f(x)/\phi(x)^2$ successfully extracted in \cite{second} the Hessian structural invariants under the name of Mika's Second Fundamental Theorem:
{\bf Theorem (Mika's Third Fundamental Theorem).} {\it For a function $f(x) \in C^3({\bf R}^n)$ and for a function $\phi(x) \in C^1({\bf R}^n)$ satisfying $\nabla \phi \ne 0$ on $\phi = 0$, the third-order division by zero value on the hypersurface $\phi(x)=0$ is given by: \begin{equation} \left.\frac{f(x)}{\phi(x)^3}\right|_{\phi=0} = \frac{1}{6|\nabla\phi|^6} \left( D^3_{\nabla\phi}f - 3 \frac{(\nabla\phi)^T H_\phi \nabla\phi}{|\nabla\phi|^2} D^2_{\nabla\phi}f + \mathcal{R}_3(f, \phi) \right), \end{equation} where $D^k_{\nabla\phi}$ denotes the $k$-th directional derivative along the normal vector $\nabla\phi$, and the third-order geometric curvature correction $\mathcal{R}_3(f, \phi)$ is given explicitly by: \begin{equation} \mathcal{R}_3(f, \phi) = 3 \left( \frac{2((\nabla\phi)^T H_\phi \nabla\phi)^2}{|\nabla\phi|^2} - (\nabla\phi)^T \left[ \sum_{k=1}^n \phi_{x_k} H_{\phi_{x_k}} \right] \nabla\phi \right) (\nabla f \cdot \nabla\phi). \end{equation} }