Okay, where was I again? Ah yes... the digraph list. Right, here is all the digraph generated in the first row:
["it","ha","pi","pt","hn","an","aa","po","io","ii","to","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","oi","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
The length of the resulting mix is the average length of the parents rounded to the next integer. But for example, let;s ignore that limitaiton. Now... we take the very first digram "it" and mark it out from the array:
"it": ["ha","pi","pt","hn","an","aa","po","io","ii","to","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","oi","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
Next, we find a digrams that start with "t" and mark it out:
"ito": ["ha","pi","pt","hn","an","aa","po","io","ii","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","oi","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
Do it until reached the desired length:
"ito": ["ha","pi","pt","hn","an","aa","po","io","ii","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","oi","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
"itoi": ["ha","pi","pt","hn","an","aa","po","io","ii","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
"itoio": ["ha","pi","pt","hn","an","aa","po","ii","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","nt","hh","hp","pp","ph","ot","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
"itoiot": ["ha","pi","pt","hn","an","aa","po","ii","na","ti","ia","tt","ip","ih","ta","ai","at","th","tp","hi","in","ht","ah","ap","pa","tn","ni","nt","hh","hp","pp","ph","ao","oa","pn","nh","np","oh","ho","op","nn","no","on","oo"]
And so forth.
What if we haven't reached the wanted length but there's no viable digrams? Well... the engine will take a step back and find for next digram.
The medial and final filter are placed to prevent the engine from making phonotactically illegal strings.