diff options
Diffstat (limited to 'src/theory')
| -rw-r--r-- | src/theory/strings/theory_strings_preprocess.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/theory/strings/theory_strings_preprocess.cpp b/src/theory/strings/theory_strings_preprocess.cpp index d1eef656b..8e057a525 100644 --- a/src/theory/strings/theory_strings_preprocess.cpp +++ b/src/theory/strings/theory_strings_preprocess.cpp @@ -309,6 +309,9 @@ Node StringsPreprocess::simplify( Node t, std::vector< Node > &new_nodes ) { lem = s.eqNode(nm->mkNode(APPLY_UF, us, d_zero)); conc2.push_back(lem); + lem = nm->mkNode(GT, lens, d_zero); + conc2.push_back(lem); + Node x = nm->mkBoundVar(nm->integerType()); Node xbv = nm->mkNode(BOUND_VAR_LIST, x); Node g = @@ -343,6 +346,7 @@ Node StringsPreprocess::simplify( Node t, std::vector< Node > &new_nodes ) { // ELSE: // stoit = U( len( s ) ) ^ U( 0 ) = 0 ^ // "" = Us( len( s ) ) ^ s = Us( 0 ) ^ + // str.len( s ) > 0 ^ // forall x. (x>=0 ^ x < str.len(s)) => // Us( x ) = Ud( x ) ++ Us( x+1 ) ^ // U( x+1 ) = ( str.code( Ud( x ) ) - 48 ) + 10*U( x ) |