3 problems

Let $(X,\Delta)$ be a semi log canonical pair, and let … be a projective morphism. A divisor is $\pi$-nef if it has nonnegative intersection with every curve contracted by $\pi$, a…

Log abundance conjecture. $K_X+\Delta$ is semi-ample.

Let $(X,\Delta)$ be a projective semi-log canonical pair. Thus $X$ is a reduced, pure-dimensional $S_2$-scheme that is normal crossing in codimension $1$, $\Delta$ is an effective…