! ============================================================
! M11 - Bug hunt
! ============================================================
/CLEAR,START                        ! Five typical failures in 3D contact pairs.
/FILNAME,m11_bug_hunt,1
/UNITS,SI

! ERROR 1: contact/target surfaces swapped.
! CONTA174 must go on the upper deformable-body face; TARGE170 on the lower one.
! CONTA174 on the lower-block face and TARGE170 on the upper one.
! Symptom: CNCHECK reports inconsistent normals or contact does not close.

! ERROR 2: ESURF without a prior area/node selection.
! ESURF requires selected areas/nodes; without ASEL/NSLA it creates no contact elements.
! ESURF immediately after VMESH,ALL without ASEL/NSLA.
! Symptom: zero CONTA/TARGE elements; n_conta=0 in the audit.

! ERROR 3: omit CNCHECK before SOLVE.
! CNCHECK,AUTO documents gap, penetration, and normal consistency before SOLVE.
! ! CNCHECK,AUTO is missing
! Symptom: initial penetration is not documented; convergence surprises.

! ERROR 4: empty REAL stiffness/attributes or incorrect TYPE when creating ESURF.
! ESURF inherits TYPE/REAL/MAT; TYPE,1 on the contact surface prevents creating CONTA174.
! TYPE,1 before ESURF on contact surfaces.
! Symptom: missing contact or extreme stiffness; excessive penetration.

/COM,DIAGNOSE: normals, ESURF, CNCHECK, REAL/TYPE, RFY vs contact_closed     ! Symptom: study_passes=1 even though the pair remains open.
/COM,Table: symptom -> check (.out, CSV) -> cause -> fix
FINISH