Function: ellmoddegree
Section: elliptic_curves
C-Name: ellmoddegree_bitprec
Prototype: Gb
Help: ellmoddegree(e): e being an elliptic curve defined over Q output by
  ellinit, compute the modular degree of e divided by the square of the
  Manin constant. Return [D, err], where D is a rational number and
  err is the exponent of the truncation error.
Doc: $e$ being an elliptic curve defined over $\Q$ output by \kbd{ellinit},
  compute the modular degree of $e$ divided by the square of
  the Manin constant. Return $[D, err]$, where $D$ is a rational number and
  err is exponent of the truncation error.
