2 problems

Let $\Phi:{\mathbb A}\xrightarrow{}{\mathbb B}$ be a matrix. Its tight extension is the matrix … obtained from the loose extension by retaining the morphisms that are mono and whos…

Let $\Phi:{\mathbb A}\looparrowright{\mathbb B}$ be a matrix. Its loose extension is the matrix … with objects $(a,b)$ and structure maps…