Signatures
   
 

The signature of a proof is a list of all the Predicates and Terms that appear inside the proof's outer layer. This is called the global signature. Boxes inside a proof may have larger signatures then the proof as they may declare skolem terms. The signature of a box controls what Predicates and Terms can be used inside it. For example, in a box created by For All Introduction which defines a new skolem term, say sk1, sk1 is available for use in terms within the box but not outside it. We call the signature local to a box the box's signature.

The global signature of a proof is set up by Pandora after you have entered the givens and the conclusion. The signature will be shown when you click on the show signature tab in the panel on the left of your proof.

If part way through a proof you think you may want addtional items in the Global Signature you can add them through the add signature item in the options menu.

To add a Predicate:

  1. Go to Options menu > Add to Signature > Predicate.
  2. Then on your left hand side just above the Rule panel you will see two text fields indicating Pred Name and Arity, Pred Name indicates the text field to type in the predicate and the Arity refers to the number of parameters the predicate takes.
  3. After you have entered the predicate name and its arity press Add to add them to the signature or press cancel if you changed your mind.

To add a Constant:

  1. Go to Options menu > Add to Signature > Constant.
  2. Then on your left hand side just above the Rule panel you will see a text field indicating Const Name into which type in the constant.
  3. After you have entered the constant name press Add to add them to the signature or press cancel if you changed your mind.

To add a Function:

  1. Go to Options menu > Add to Signature > Function.
  2. Then on your left hand side just above the Rule panel you will see two text fields indicating Func Name and Arity, Func Name indicates the text field to type in the function and the Arity refers to the number of parameters the function takes.
  3. After you have entered the function name and its arity press Add to add them to the signature or press cancel if you changed your mind.