What do terms of net 13Th 23Rd prox 3Rd 13Th subsequent mean?

The terms "net 13th, 23rd, prox, 3rd, 13th subsequent" refer to payment terms in financial agreements. "Net" indicates that the full amount is due without any deductions. "13th" and "23rd" specify specific days of the month when payment is due, while "prox" means payments are due at the end of the month following the invoicing month. "3rd" and "13th subsequent" suggest that payments are due on the 3rd and 13th of the month after the invoice date.