Merge #31877

sagemath · Jun 21, 2021 · e768463 · e768463
2 parents bc26d4f + 5b0f85d
commit e768463
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Showing 2 changed files with 170 additions and 49 deletions.
diff --git a/src/sage/functions/piecewise.py b/src/sage/functions/piecewise.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 r"""
 Piecewise-defined Functions
 
@@ -527,7 +528,7 @@ def restriction(self, parameters, variable, restricted_domain):
                 sage: f = piecewise([((-oo, oo), x)]);  f
                 piecewise(x|-->x on (-oo, +oo); x)
                 sage: f.restriction([[-1,1], [3,3]])
-                piecewise(x|-->x on [-1, 1] + {3}; x)
+                piecewise(x|-->x on [-1, 1] ∪ {3}; x)
             """
             restricted_domain = RealSet(*restricted_domain)
             new_param = []
@@ -559,7 +560,7 @@ def extension(self, parameters, variable, extension, extension_domain=None):
                 ValueError: point 3 is not in the domain
 
                 sage: g = f.extension(0);  g
-                piecewise(x|-->x on (-1, 1), x|-->0 on (-oo, -1] + [1, +oo); x)
+                piecewise(x|-->x on (-1, 1), x|-->0 on (-oo, -1] ∪ [1, +oo); x)
                 sage: g(3)
                 0
 
@@ -583,7 +584,7 @@ def unextend_zero(self, parameters, variable):
                 sage: f = piecewise([((-1,1), x)]);  f
                 piecewise(x|-->x on (-1, 1); x)
                 sage: g = f.extension(0);  g
-                piecewise(x|-->x on (-1, 1), x|-->0 on (-oo, -1] + [1, +oo); x)
+                piecewise(x|-->x on (-1, 1), x|-->0 on (-oo, -1] ∪ [1, +oo); x)
                 sage: g(3)
                 0
                 sage: h = g.unextend_zero()
@@ -652,7 +653,7 @@ def piecewise_add(self, parameters, variable, other):
                 sage: f = piecewise([([0,1], 1), ((2,3), x)])
                 sage: g = piecewise([((1/2, 2), x)])
                 sage: f.piecewise_add(g).unextend_zero()
-                piecewise(x|-->1 on (0, 1/2], x|-->x + 1 on (1/2, 1], x|-->x on (1, 2) + (2, 3); x)
+                piecewise(x|-->1 on (0, 1/2], x|-->x + 1 on (1/2, 1], x|-->x on (1, 2) ∪ (2, 3); x)
             """
             points = ([minus_infinity] +
                       sorted(set(self.end_points() + other.end_points())) +