  The Sun is the most studied of stars and a laboratory of fundamental physics.
However, the understanding of our star is stained by the solar modelling
problem which can stem from various causes. We combine inversions of sound
speed, an entropy proxy and the Ledoux discriminant with the position of the
base of the convective zone and the photospheric helium abundance to test
combinations of ingredients such as equation of state, abundance and opacity
tables. We study the potential of the inversions to constrain ad-hoc opacity
modifications and additional mixing in the Sun. We show that they provide
constraints on these modifications to the ingredients and that the solar
problem likely occurs from various sources and using phase shifts with our
approach is the next step to take.
