Hi, on line 193 it should be \rrbracket: \installmathfencepair \ulcorner \Luppercorner \urcorner \Ruppercorner \installmathfencepair \llcorner \Llowercorner \lrcorner \Rlowercorner \installmathfencepair \lmoustache \Lmoustache \rmoustache \Rmoustache -\installmathfencepair \llbracket \Lopenbracket \lrbracket \Ropenbracket +\installmathfencepair \llbracket \Lopenbracket \rrbracket \Ropenbracket \installmathfencepair \lgroup \Lgroup \rgroup \Rgroup Wolfgang