Chain of Separable Binary Goppa Codes and Their Minimal Distance

It is shown that subclasses of separable binary Goppa codes, Gamma(L,G) - codes, with L={alpha isin GF(2^2l):G(alpha) ne 0 } and special Goppa polynomials G(x) can be presented as a chain of embedded and equivalent codes. The true minimal distance has been obtained for all codes of the chain.