Hamming bound: d_L(AACT,AGCT) = d_H(AACT,AGCT) = 1; d_L ≤ d_H for |x|=|y|

Sympy/stdlib-exact witness of the Hamming-upper-bounds-Levenshtein inequality on DNA anchor pairs. Setup: (i) AACT vs AGCT — differ only at position 2 (A→G), so d_H = 1 and d_L = 1 (the single substitution is optimal); (ii) ACGT vs TGCA —…