public ModInt <ModT> Decr(ModInt <ModT> val) => val--;
public ModInt <ModT> Not(ModInt <ModT> val) => throw new NotImplementedException();
public ModInt <ModT> Neg(ModInt <ModT> val) => - val;
public ModInt <ModT> Incr(ModInt <ModT> val) => val++;
public ModInt <ModT> Shr(ModInt <ModT> val, int cnt) => throw new NotImplementedException();
public ModInt <ModT> Mod(ModInt <ModT> a, ModInt <ModT> b) => throw new NotImplementedException();
public bool Neq(ModInt <ModT> a, ModInt <ModT> b) => a != b;
public bool Gte(ModInt <ModT> a, ModInt <ModT> b) => throw new NotImplementedException();
public bool Eq(ModInt <ModT> a, ModInt <ModT> b) => a == b;
public ModInt <ModT> Div(ModInt <ModT> a, ModInt <ModT> b) => a / b;
public ModInt <ModT> Mul(ModInt <ModT> a, ModInt <ModT> b) => a * b;
public ModInt <ModT> Sub(ModInt <ModT> a, ModInt <ModT> b) => a - b;
public ModInt <ModT> Add(ModInt <ModT> a, ModInt <ModT> b) => a + b;
