id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
24255 Warn with substitution of derived classes using equality rws "There is a long-standing problem with substitution in that some substitutions do not work when given as equality but do work when given as dictionary.
{{{
sage: (x*pi).subs(x*pi==e)
x*pi
sage: (x*pi).subs({x*pi:e})
e
sage: s = x.series(x,2); s
1*x + Order(x^2)
sage: (x*pi).subs(x*pi==s)
pi*x
}}}
It looks like that in some cases the conversion to dict switches lhs and rhs of the equation and this is because of such behaviour:
{{{
sage: x*pi==e
e == pi*x
sage: x == s
1*x + Order(x^2) == x
}}}
" defect new major sage-8.2 symbolics N/A