Methods for testing By the Chinese Remainder Theorem, it suffices to test irreps of prime power level, so those are the irreps handled by the functions in this section.
Testing the group \mathrm{SL}_2(\mathbb{Z}/p^\lambda\mathbb{Z}) with conjugacy classes set to the format we use.

a list representing a character of \mathrm{SL}_2(\mathbb{Z}/p^\lambda\mathbb{Z}). Converts the modular data (S,T), which must have level dividing p^\lambda, into a character of \mathrm{SL}_2(\mathbb{Z}/p^\lambda\mathbb{Z}), presented in a form matching the conjugacy classes used in `SL2WithConjClasses`. a boolean. Constructs and tests all non-trivial irreps of level dividing p^\lambda by checking their positions in `Irr(G)` (see https://www.gap-system.org/Manuals/doc/ref/chap71.html#X873B3CC57E9A5492 Section 71.8-2 of the GAP Manual). Note that this function will print information on the irreps involved if `InfoSL2Reps` is set to level 1 or higher; see Section . a boolean. Constructs and tests all irreps of level p^\lambda, confirming that the S-matrix is symmetric and unitary and the T matrix is diagonal. Note that this function will print information on the irreps involved if `InfoSL2Reps` is set to level 1 or higher; see Section .