Stagnation line behind a detached bow shock wave in plane flows

Using the example of an ideal incompressible fluid, the fallacy of the idea that a plane flow can be considered as a limiting state of a spatial flow is shown. Thus, the problem of theoretical aerodynamics, which in recent years is considered solved, is discovered. This is the problem of a rigorous substantiation, within the framework of the Euler equations, of the possibility of the stagnation line coinciding with the leading streamline (which intersects a shock along the normal) for a plane stationary flow of an ideal perfect gas formed in a supersonic homogeneous oncoming flow behind a detached shock wave in front of a body with a smooth convex nose in the general case (an asymmetric streamlined body or a symmetrical body at incidence). This problem is considered solved because for a three-dimensional flow (not degenerated into a flat flow), the fact that the stagnation line coincides with the leading streamline was strictly substantiated in 2019. However, the revealed erroneousness of the idea of a flat flow as a limiting state of a spatial flow does not allow us to consider this fact proven for flat flows. Using a state-registered software package, numerical calculations of plane flows are carried out, which shows that even the maximum accuracy of such calculations does not allow us to give an affirmative or negative answer to the question of whether the stagnation line coincides with the leading streamline.