Re: How to Extract Conditional Expression?

*To*: mathgroup at smc.vnet.net*Subject*: [mg127589] Re: How to Extract Conditional Expression?*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sun, 5 Aug 2012 14:58:34 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120805063431.92A6F6766@smc.vnet.net>

expr = x -> ConditionalExpression[#1^2 + 3 #1 + 2 C[1], C[1] in Integers]; f[x_] = expr[[-1, 1]] /. {Slot[1] -> x, C[1] -> 3} 6 + 3 x + x^2 However, I suspect that the condition is actually Element[C[1], Integers] expr = x -> ConditionalExpression[#1^2 + 3 #1 + 2 C[1], Element[C[1], Integers]]; f[x_] = Assuming[expr[[-1, -1]], Simplify[expr[[-1]]]] /. {Slot[1] -> x, C[1] -> 3} 6 + x (3 + x) And if the original expr also actually included a pure function expr = x -> ConditionalExpression[#1^2 + 3 #1 + 2 C[1] &, Element[C[1], Integers]]; f[x_] = Assuming[expr[[-1, -1]], Simplify[expr[[-1]] /. C[1] -> 3]][x] 6 + 3 x + x^2 Depending on how your original expression was generated, you might be able to remove the condition earlier with an option such as GenerateConditions -> False Bob Hanlon On Sun, Aug 5, 2012 at 2:34 AM, ScottG <sbg at acw.com> wrote: > I have ... > > x -> ConditionalExpression[#1^2 + 3 #1 + 2 C[1], C[1] in Integers] > > and I want > > f[x_] = x^2 + 3 x + 6 > > How do I get there other than cut-and-paste? > > Thanks for any insight. > > Cheers, Scott > > >

**References**:**How to Extract Conditional Expression?***From:*ScottG <sbg@acw.com>