Add Rabin & Streett indices

client/src/LtlApp.js

 /* -*- coding: utf-8 -*-
-** Copyright (C) 2018, 2019 Laboratoire de Recherche et Développement de
+** Copyright (C) 2018-2020 Laboratoire de Recherche et Développement de
 ** l'Epita.
 **
 ** This application is free software; you can redistribute it and/or
@@ -247,6 +247,9 @@ const styles = theme => ({
     paddingBottom: 10
   },
   stutterdiv: {},
+  indexdiv: {
+    paddingBottom: 10
+  },
   livenessdiv: {
     paddingBottom: 10
   },
@@ -944,6 +947,41 @@ class LtlStudy extends React.Component {
             </Typography>
           )}
         </div>
+        <div className={this.props.classes.indexdiv}>
+          <Typography variant="body2" color="primary">
+            Indices
+          </Typography>
+          {(res["Rabin_index"] !== null || res["Streett_index"] !== null) && (
+            <Table className={this.props.classes.wordtable}>
+              <TableBody>
+                <TableRow className={this.props.classes.wordtablerow}>
+                  <TableCell
+                    component="th"
+                    scope="row"
+                    className={this.props.classes.wordtablecell}
+                  >
+                    Rabin index:
+                  </TableCell>
+                  <TableCell className={this.props.classes.wordtablecellw}>
+                    {res["Rabin_index"]}
+                  </TableCell>
+                </TableRow>
+                <TableRow className={this.props.classes.wordtablerow}>
+                  <TableCell
+                    component="th"
+                    scope="row"
+                    className={this.props.classes.wordtablecell}
+                  >
+                    Streett index:
+                  </TableCell>
+                  <TableCell className={this.props.classes.wordtablecellw}>
+                    {res["Streett_index"]}
+                  </TableCell>
+                </TableRow>
+              </TableBody>
+            </Table>
+          )}
+        </div>
         <div className={this.props.classes.satisfiabilitydiv}>
           <Typography variant="body2" color="primary">
             Satisfiability

server/spotapi.py

 #!/usr/bin/python3
 # -*- coding: utf-8 -*-
-# Copyright (C) 2018-2019 Laboratoire de Recherche et Développement de
+# Copyright (C) 2018-2020 Laboratoire de Recherche et Développement de
 # l'Epita.
 #
 # This application is free software; you can redistribute it and/or
@@ -331,6 +331,27 @@ def study(ltlformula, method='GET'):
         else:
             result['rej_word'] = None;
 
+    # Rabin and Streett indices
+    # This is done my calling reduce_parity() on a deterministic
+    # parity automaton.
+    # Note that f2 is relabeled, so do not attempt to reuse
+    # pos as-is after this block.
+    if not spot.is_deterministic(pos):
+        pos = spot.translate(f2, 'medium', 'generic', 'deterministic')
+    isparity, ismax, isodd = pos.acc().is_parity()
+    if not isparity:
+        pos = spot.to_parity(pos)
+    spot.complete_here(pos)
+    spot.change_parity_here(pos,
+                            spot.parity_kind_max, spot.parity_style_any)
+    pos = spot.reduce_parity(pos)
+    isparity, ismax, isodd = pos.acc().is_parity()
+    assert isparity
+    assert ismax
+    ns = pos.num_sets() + 1
+    result['Rabin_index'] = (ns + int(isodd)) // 2
+    result['Streett_index'] = (ns + int(not isodd)) // 2
+
     return jsonify(result)
 
 # Input parameters