Determine all subsequences of the first sequence. A subsequence is a sequence found within a sequence. In this example, the first sequence is the word "plea" and the second sequence is the word "apple." The subsequences of the word "plea" are "pl," "pe," "pa," "le," "la," "ea," "ple," "pla," "pea," "lea" and "plea."
Determine all subsequences of the second sequence. In this case, the subsequences of the word "apple" are "ap," "al," "ae," "pp," "pl," "pe," "le," "app," "apl," "ape," "ppl," "ple," "appl," "pple" and "apple."
Compare the subsequences of the two sequences and write down all common subsequences. In this case, the subsequences found in both "plea" and "apple" are "pl", "pe", "le" and "ple."
Determine the longest common subsequence, which is the longest subsequence found in both sequences. In this case, the longest common subsequence between "plea" and "apple" is "ple."