====== "fault" command ======

===== Purpose =====

Temporarily change a component value. 

===== Syntax =====

  fault partlabel=value ... 
  unfault

===== Comments =====

This command quickly changes the value of a component, usually with the intention that you will not want to save it.

If you apply this command to a nonlinear or otherwise strange part, it becomes ordinary and linear until the fault is removed.

It is an error to fault a model call.

If several components have the same label, the fault value applies to all of them. (They will all have the same value.)

The unfault command restores the old values. 

===== Example =====

  fault R66=1k
R66 now has a value of 1k, regardless of what it was before.
  unfault
Clears all faults. In this case, R66 has its old value again.

unfault can bring on surprises. Consider this sequence ... 
  V1   1   0    ac  1
  C3   1   2    1u
  R4   2   0    10k

  fault C3=100p
C3 is 100 picofarads, for now.
  modify C3=220p
C3 is 220 pf, for now. It will be restored.
  modify R4=1k
R4 is 1k. It will not be restored.
  unfault
C3 back to 1 uf, but R4 still 1k.