2 problems

Let $n$ be a positive integer and let $a,b,c,d$ satisfy $1\leq a,b,c,d<n$, $a+b>n$, and $a+b+c+d=2n$. Let $F$ be the cluster-algebra function on…

Let $x_1,x_2,x_3$ be points in the affine Grassmannian, and let $\omega_i,\omega_j,\omega_k$ be fundamental weights of $SL_n$ with $i+j+k=n$. For points $p,q$ in the affine Grassma…