A numeral (saṃkhyā) may be compounded with the names of 'rivers' and the resulting compound is avyayībhāva denoting an aggregate.,
According to Patanjali this refers to their Aggregate (समाहार); as सप्तगङ्गम् ' at the meeting of the seven Ganges,' द्वियमुनं 'at the meeting of the two Yamunas,' पञ्चनदं' where the five rivers meet'. सप्तगोदावरम् 'where seven Godavaris' meet.,