4.34 Next

Positioning on the next unproved proof obligation

Syntax

  ne

Use

This command allows the user to go on to the next unproved proof obligation, if there is one. If there are no more unproved proof obligations, the ne command is ineffective.

This command can be used to go quickly to the first proof to be checked when the interactive proof of a component is opened.

Example

The component is made up of clause Initialisation and operation Calculus, two proof obligations which have been proved, and two unproved proof obligations. By using the gs (see chapter 4.22 page §) command, the following situation can be obtained:


 
PRI> gs  
State of all PO  
    Initialisation  
        PO1 Proved      not(e5 = e1)  
        PO2 Proved      e1 = e5  
    Calculus  
        PO1 Unproved    not(e2 = e5)  
        PO2 Unproved    e5 = e1  
End  
 


Let us suppose that the current proof obligation is Calculus.1. The user moves on to the next unproved proof obligation.


 
PRI> ne  
Current PO : Calculus.2  
 


By repeating this command, the user finds himself back to the proof obligation Calculus.1.


 
PRI> ne  
Current PO : Calculus.1