Ticket #8237: trac_8237-maxima_infinity.take2.patch

sage/calculus/calculus.py

@@ -986 +986 @@
         -x/sqrt(-x^2 + 1)
         sage: limit(g, x=1, dir='below')
         -Infinity
+
+    TESTS::
+
+        sage: limit(1/x,x=0)
+        Infinity
+        sage: limit(1/x,x=0,dir='above')
+        +Infinity
+        sage: limit(1/x,x=0,dir='below')
+        -Infinity
     """
     if not isinstance(ex, Expression):
         ex = SR(ex)
@@ -1428 +1437 @@
 symtable = {'%pi':'pi', '%e': 'e', '%i':'I', '%gamma':'euler_gamma',
             'li[2]':'polylog2', 'li[3]':'polylog3'}
 
-from sage.symbolic.pynac import register_symbol
-from sage.rings.infinity import infinity, minus_infinity
-register_symbol(infinity, dict(maxima='inf'))
-register_symbol(minus_infinity, dict(maxima='minf'))
-
 from sage.misc.multireplace import multiple_replace
 
 import re
@@ -1476 +1480 @@
         sage: a.sage()
         x != 0
     """
+    global _syms
+    _syms = sage.symbolic.pynac.symbol_table.get('maxima', {})
     syms = dict(_syms)
 
     if len(x) == 0:

sage/calculus/functional.py

@@ -311 +311 @@
         sage: lim(exp(x), x=-oo)
         0
         sage: lim(1/x, x=0) 
-        +Infinity
+        Infinity
         sage: limit(sqrt(x^2+x+1)+x, taylor=True, x=-oo)
         -1/2
         sage: limit((tan(sin(x)) - sin(tan(x)))/x^7, taylor=True, x=0)

sage/symbolic/constants.py

@@ -197 +197 @@
     13.271347940197249310098819199575813940871106820003074817832971189555
     sage: RDF(a)
     13.2713479402
+
+Test if #8237 is fixed::
+
+    sage: maxima('infinity').sage()
+    Infinity
+    sage: maxima('inf').sage()
+    +Infinity
+    sage: maxima('minf').sage()
+    -Infinity
 """
 ###############################################################################
 #   Sage: Open Source Mathematical Software
 #       Copyright (C) 2008 William Stein <wstein@gmail.com>
-#       Copyright (C) 2008 Burcin Erocal <burcin@erocal.org>
+#       Copyright (C) 2008-2010 Burcin Erocal <burcin@erocal.org>
 #                     2009 Mike Hansen <mhansen@gmail.com>
 #  Distributed under the terms of the GNU General Public License (GPL),
 #  version 2 or any later version.  The full text of the GPL is available at:
@@ -218 +227 @@
 constants_name_table[repr(unsigned_infinity)] = unsigned_infinity
 constants_name_table[repr(minus_infinity)] = minus_infinity
 
+import sage.symbolic.pynac
+sage.symbolic.pynac.register_symbol(infinity, {'maxima':'inf'})
+sage.symbolic.pynac.register_symbol(minus_infinity, {'maxima':'minf'})
+sage.symbolic.pynac.register_symbol(unsigned_infinity, {'maxima':'infinity'})
+
 def unpickle_Constant(class_name, name, conversions, latex, mathml, domain):
     """
     EXAMPLES::