588. Exemptions from charge.

The charge under these provisions1 does not apply to a person at a time when his estate includes2:

  1.  

    (1)     the relevant property3 or other property which derives its value from the relevant property, and the value of which, so far as attributable to the relevant property, is not substantially less than the value of that property4;

  2.  

    (2)     the relevant property, or any other property which derives its value from the relevant property and the value of which, so far as referable to the relevant property, is not substantially less than the value of the relevant property, provided that one