The Igusa-Todorov function for comodules
  We define the Igusa-Todorov function in the context of finite dimensional comodules and prove that a coalgebra is left qcF if and only if it is left semiperfect and its Igusa-Todorov function on each right finite dimensional comodule is zero. 
Haim Mariana, Lanzilotta Marcelo and Mata Gustavo
math.RT math.KT