Hello Happy to report that Luatex made my life easier once again. :) I've made another test papers for my students, with varying problems, and it was possible only due to Lua emedded code. Examples: Perform logical AND, OR and XOR under the following pair of hexadecimal numbers: \startluacode n = math.random(10,255) m = math.random(10,255) tex.print(string.format("%X, %X", n, m)) \stopluacode Encode your Name and Surname as a \startluacode a = {'null-terminated', 'dollar-terminated', 'Pascal'} tex.print( string.format('%s string.', a[math.random(1,3)]) ); \stopluacode Lucky, the discussion about Lua reference started in the list today, because I need more knowledge of Lua to make even more flexible assignments. Best regards, Vyatcheslav