Singularities for projections of contour lines of surfaces onto planes (Q5957952)

A contour line of a surface \(S\) in \({\mathbb R}^3=\{x,y,z\}\) is a set \(S\cap\{z=\text{const}\}\). The author studies semi-local patterns of the visual image when a surface is looked at with its contour lines from another point of \({\mathbb R}^3\). This amounts to the study of divergent diagrams of smooth mappings \({\mathbb R}\leftarrow M\to{\mathbb R}^2\), where \(M\) is a smooth surface. NEWLINENEWLINENEWLINEThe author gives a generic semi-local classification of such divergent diagrams and gives a list of normal forms (which contain functional moduli).