(b) Medium-term normal imprisonment, defined as deprivation of liberty for periods of between 1 and 12 years, which must be served in a prison or a special agricultural penal colony and which involves the performance of work exclusively within the custodial establishment (arts. 36 and 60);
(b) Medium-term normal imprisonment, defined as deprivation of liberty for periods of between 1 and 12 years, which must be served in a prison or a special agricultural penal colony and which involves the performance of work exclusively within the custodial establishment (arts. 36 and 60)；