Add missing bound from dtypes for sign special cases

Author: honno

array_api_tests/test_special_cases.py

@@ -941,12 +941,18 @@ def _x2_cond_from_dtype(dtype, **kw) -> st.SearchStrategy[float]:
                 def partial_cond(i1: float, i2: float) -> bool:
                     return math.copysign(1, i1) == math.copysign(1, i2)
 
+                x1_cond_from_dtypes.append(BoundFromDtype(kwargs={"min_value": 1}))
+                x2_cond_from_dtypes.append(BoundFromDtype(kwargs={"min_value": 1}))
+
             elif value_str == "different mathematical signs":
                 partial_expr = "copysign(1, x1_i) != copysign(1, x2_i)"
 
                 def partial_cond(i1: float, i2: float) -> bool:
                     return math.copysign(1, i1) != math.copysign(1, i2)
 
+                x1_cond_from_dtypes.append(BoundFromDtype(kwargs={"min_value": 1}))
+                x2_cond_from_dtypes.append(BoundFromDtype(kwargs={"max_value": -1}))
+
             else:
                 unary_cond, expr_template, cond_from_dtype = parse_cond(value_str)
                 # Do not define partial_cond via the def keyword or lambda