Thanks Aditya, but it does not work what it should? With: \defineenumeration[demo][text={Demostració.\space},number=no, location=serried,width=fit,headstyle=italic,indentnext=yes, between=\blank,textdistance=.5em,closesymbol={\mathematics{\Box}}, style=normal,indenting=yes] and \starttext \startdemo Si $\text{area}(u) = N$ i $\text{area}(v) = M$, aleshores \startformula \startmathalignment \NC u \NC = \prod_{i=1}^N x_i^{-1} r_i x_i, \NR[+] \NC v \NC = \prod_{j=1}^M y_j^{-1} s_j y_j, \NR[+] \stopmathalignment \stopformula% per a alguns $x_i, y_j \in F(A)$, $r_i, s_j \in R$, on aquestes igualtats són dins el grup lliure $F(A)$. Com que $w = u v$ també dins el grup lliure, tenim que \placeformula[-] \startformula \startsplit \NC w = u v \NC = \bigl( \prod_{i = 1}^N x_i^{-1} r_i x_i \bigr) \cdot \bigl( \prod_{j=1}^M y_j^{-1} s_j y_j \bigr) \NR \NC \NC = (x_1^{-1} r_1 x_1)\cdots (x_N^{-1} r_N x_N) \cdot (y_1^{-1} s_1 y_1) \cdots (y_M^{-1} s_M y_M) \NR \NC \NC = \prod_{k=1}^{M+N} z_k^{-1} t_k z_k \stopsplit \stopformula on \startformula z_k = \startcases \NC x_k \MC 1 \leq k \leq N \NR \NC y_{k-N} \MC N+1 \leq k \leq N+M, \NR \stopcases t_k = \startcases \NC r_k \MC 1 \leq k \leq N \NR \NC s_{k-N} \MC N+1 \leq k \leq N+M. \NR \stopcases \stopformula Llavors, per definició, $\text{area}(w) \leq N+M = \text{area}(u) + \text{area}(v)$. \stopdemo \stoptext I have that "per a alguns" is indenting but "on" is not. Why? Xan. PS: Please, CCme