package G4ip;+
−
+
−
import java.util.Vector;+
−
import G4ip.Form.*;+
−
+
−
/** Context acts as a multiset.<p>+
−
  * Typical contexts in logical rules are Gamma, Delta, etc.+
−
  * @author      Christian Urban+
−
  */+
−
public class Context extends Vector {+
−
  +
−
  public Context() { super(); }+
−
+
−
  public Context(Context init_context) {+
−
    super();+
−
    for (int i=0;i<init_context.size();i++) {+
−
      addElement(init_context.elementAt(i));+
−
    }+
−
  }+
−
+
−
  /** should be toString, but this is a "final" method in Vector +
−
    */+
−
  public String makeString() {+
−
    String s = new String();+
−
    int i;                      // size()-1 because the last formula+
−
    for (i=0;i<size()-1;i++) {  // should be printed without a comma+
−
      s=s.concat(elementAt(i).toString());+
−
      s=s.concat(", ");+
−
    }+
−
    if (size() > 0) {           // add last formula +
−
      s=s.concat(elementAt(i).toString()); +
−
    }+
−
    return s;+
−
  }+
−
+
−
  /** returns a context with one additional formula at the beginning +
−
    * @param   new_formula    a formula+
−
    */+
−
  public Context add(Form new_formula) {+
−
    Context new_c = new Context(this);+
−
    new_c.insertElementAt(new_formula,0);+
−
    return new_c;+
−
  }+
−
+
−
  /** returns a context with two additional formulae at the beginning +
−
    * @param new_formula1,new_formula2    two formulae+
−
    */+
−
  public Context add(Form new_formula1, Form new_formula2) {+
−
    Context new_c = new Context(this);+
−
    new_c.insertElementAt(new_formula1,0);+
−
    new_c.insertElementAt(new_formula2,0);+
−
    return new_c;+
−
  }+
−
+
−
  /** tests whether a context contains a specific atom +
−
    * @param a a formula+
−
    */+
−
  public boolean includes(Form a) {+
−
    if (a instanceof Atm) {+
−
      for (int i=0;i<size();i++) {+
−
        switch((Form)elementAt(i)) {+
−
        case Atm(String c):+
−
          if (c.compareTo(((Atm)a).c) == 0) return true; break;+
−
        }+
−
      }+
−
    }+
−
    return false;+
−
  }+
−
+
−
}+
−