Hi Xan, It's not exactly what you want, but maybe it'll give you some other ideas: \definemathmatrix[pmatrix][ left={\left(\,}, right={\,\right)}, ] \definenumber[pmatrix] \resetnumber[pmatrix] \define\nextmatrix{ \incrementnumber[pmatrix] \getnumber[pmatrix]. } \define[2]\pmatrices{ \blank[big] \framed[frame=off]{ \startmixedcolumns[n=#1] #2 \stopmixedcolumns } } \starttext Digueu quines de les matrius següents són regulars. Quan ho siguin, trobeu la inversa \pmatrices{4}{ \nextmatrix \startpmatrix \NC 2 \NC 3 \NR \NC 6 \NC 7 \NR \stoppmatrix \column \nextmatrix \startpmatrix \NC 3 \NC 2 \NC 1 \NR \NC 4 \NC 5 \NC 3 \NR \NC 5 \NC 0 \NC -2 \NR \stoppmatrix \column \nextmatrix \startpmatrix \NC 5 \NC 4 \NC 2 \NR \NC 2 \NC 2 \NC 3 \NR \NC 7 \NC 6 \NC 5 \NR \stoppmatrix \column \nextmatrix \startpmatrix \NC a \NC 0 \NC 0 \NC 0 \NR \NC 0 \NC b \NC 0 \NC 0 \NR \NC 0 \NC 0 \NC c \NC 0 \NR \NC 0 \NC 0 \NC 0 \NC d \NR \stoppmatrix } \stoptext