Hi, Are you delete the command \snappedmath? I get that: ! Undefined control sequence. system > tex > error on line 834 in file /home/xan/SYNC/cepasud-raw/classe/ESPA3/planificació/Tema2-Àlgebra/80-juntat.conTeXt: Undefined control sequence ... 824 % TODO: acabar les solucions 825 TODO 826 (Solucions: \startitemize[a,text] \item $x = -1$ \item $x = -1$ \item $x = -2$ \item $x = 3$\stopitemize) 827 \stopmode 828 \stopexercici 829 830 \startexercici Resol: 831 832 \startitemize[a,columns] 833 834 >> \item \snappedmath {\displaystyle 3x- (x-2) = 4x + 1} 835 836 \item \snappedmath {\displaystyle 4\left(x+3\right)-\left(2x-7\right) = 6x + 18} 837 838 \item \snappedmath {\displaystyle 5-(3-x) = 2(x+2) -3} 839 840 \item \snappedmath {\displaystyle 2x-\left(9x+2\right)+4x = 43-x+8-x-13} 841 842 \item \snappedmath {\displaystyle 2(x-2) -(5-x)=3x+2-6(x+2)} 843 844 \item \snappedmath {\displaystyle 2x-\left(x-3\right) -2\left(5-x\right) = 6-x +8x-1} <recently read> \snappedmath l.834 \item \snappedmath {\displaystyle 3x- (x-2) = 4x + 1} ? Thanks,