Tatsuya can read activation sequences, Mahouka Vol 1

"Impressive. You seem to be able to read and understand expanded activation programs."
Activation programs were vast clumps of data for constructing magic programs. Magicians could intuitively understand what sort of effects a magic program possessed. During the process where a magic program interferes with eidos, a magician could "read" what sort of alteration the magic program was trying to achieve by the reaction given from the eidos, which resisted the alteration. But the activation program was nothing more than a cluster of data on its own. And it was an immense amount of data, too. Even the magician who expanded it would only be able to semiautomatically process it unconsciously. Reading an activation program was like being able to visualize an image in your head by looking only at the digits making up the image's data. Normally you couldn't understand such a thing consciously. "My practical abilities are subpar, but analysis is a speciality of mine."