Definition Pcond_simpl_complete :=
  fcons_ok _ PFcons2_fcons_inv.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record field_theory : Prop := mk_field {
    F_R : ring_theory rO rI radd rmul rsub ropp req;
    F_1_neq_0 : ~ 1 == 0;
    Fdiv_def : forall p q, p / q == p * / q;
    Finv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Definition F2AF f :=
    mk_afield
      (Rth_ARth Rsth Reqe (F_R f)) (F_1_neq_0 f) (Fdiv_def f) (Finv_l f).Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Record semi_field_theory : Prop := mk_sfield {
    SF_SR : semi_ring_theory rO rI radd rmul req;
    SF_1_neq_0 : ~ 1 == 0;
    SFdiv_def : forall p q, p / q == p * / q;
    SFinv_l : forall p, ~ p == 0 ->  / p * p == 1
  }.Definition SF2AF R (rO rI:R) radd rmul rdiv rinv req Rsth
    (sf:semi_field_theory rO rI radd rmul rdiv rinv req)  :=
    mk_afield _ _
      (SRth_ARth Rsth (SF_SR sf))
      (SF_1_neq_0 sf)
      (SFdiv_def sf)
      (SFinv_l sf).Notation "0" := rO.Notation "1" := rI.Notation "x + y" := (radd x y).Notation "x * y " := (rmul x y).Notation "x - y " := (rsub x y).Notation "- x" := (ropp x).Notation "x / y " := (rdiv x y).Notation "/ x" := (rinv x).Notation "x == y" := (req x y) (at level 70, no associativity).Add Parametric Relation : R req
     reflexivity  proved by (@Equivalence_Reflexive _ _ Rsth)
     symmetry     proved by (@Equivalence_Symmetric _ _ Rsth)
     transitivity proved by (@Equivalence_Transitive _ _ Rsth)
    as R_setoid3.Add Morphism radd with signature (req ==> req ==> req) as radd_ext3.Add Morphism rmul with signature (req ==> req ==> req) as rmul_ext3.Add Morphism ropp with signature (req ==> req) as ropp_ext3.

Lemma ring_S_inj x y : 1+x==1+y -> x==y.