System for generation of oxygen by low-temperature air separation having - a high-pressure column and a low-pressure column, - a main condenser which is constructed as a condenser-evaporator, wherein the liquefaction space of the main condenser is flow-connected (13, 14, 15) to the top of the high-pressure column and the evaporation space of the main condenser is flow-connected (31, 33, 34, 35) to the low-pressure column, - an oxygen product line that is connected to the low-pressure column, - an auxiliary column, - means for introducing a gaseous fraction, the oxygen content of which is equal to that of air or higher, into the sump region of the auxiliary column and having - a reflux liquid line (19, 20, 20b) for introducing a liquid stream from the high-pressure column, the main condenser, or the low-pressure column as reflux to the top of the auxiliary column, wherein the liquid stream has a nitrogen content that is at least equal to that of air, - an argon removal column that is flow-connected (29, 30) to an intermediate site of the low-pressure column, - an argon removal column top condenser that is constructed as a condenser-evaporator, wherein the liquefaction space of the argon removal column top condenser is flow-connected (38, 39) to the top of the argon removal column, - a crude oxygen line (21, 22) for introducing liquid crude oxygen from the sump of the high-pressure column into the evaporation space of the argon removal column top condenser, wherein - the main condenser is arranged over the high-pressure column and - the argon removal column top condenser is arranged over the argon removal column, characterized in that - the low-pressure column is arranged beside the high-pressure column, - the auxiliary column is arranged over the main condenser and - the argon removal column is arranged over the auxiliary column. - a high-pressure column and a low-pressure column, - a main condenser which is constructed as a condenser-evaporator, wherein the liquefaction space of the main condenser is flow-connected (13, 14, 15) to the top of the high-pressure column and the evaporation space of the main condenser is flow-connected (31, 33, 34, 35) to the low-pressure column, - an oxygen product line that is connected to the low-pressure column, - an auxiliary column, - means for introducing a gaseous fraction, the oxygen content of which is equal to that of air or higher, into the sump region of the auxiliary column and having - a reflux liquid line (19, 20, 20b) for introducing a liquid stream from the high-pressure column, the main condenser, or the low-pressure column as reflux to the top of the auxiliary column, wherein the liquid stream has a nitrogen content that is at least equal to that of air, - an argon removal column that is flow-connected (29, 30) to an intermediate site of the low-pressure column, - an argon removal column top condenser that is constructed as a condenser-evaporator, wherein the liquefaction space of the argon removal column top condenser is flow-connected (38, 39) to the top of the argon removal column, - a crude oxygen line (21, 22) for introducing liquid crude oxygen from the sump of the high-pressure column into the evaporation space of the argon removal column top condenser, wherein - the main condenser is arranged over the high-pressure column and - the argon removal column top condenser is arranged over the argon removal column, characterized in that - the low-pressure column is arranged beside the high-pressure column, - the auxiliary column is arranged over the main condenser and - the argon removal column is arranged over the auxiliary column. - the main condenser is arranged over the high-pressure column and - the argon removal column top condenser is arranged over the argon removal column, - the low-pressure column is arranged beside the high-pressure column, - the auxiliary column is arranged over the main condenser and - the argon removal column is arranged over the auxiliary column.