Re: How to check whether an infinite set is closed under

*To*: mathgroup at smc.vnet.net*Subject*: [mg124288] Re: How to check whether an infinite set is closed under*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Mon, 16 Jan 2012 17:05:34 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201201150951.EAA19688@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

"Given k positive numbers a_1<a_2<a_3<...<a_k", how do we know what the other numbers "a_k + 1, a_k+2, ......" might be? Bobby On Sun, 15 Jan 2012 03:51:49 -0600, Rex <aoirex at gmail.com> wrote: > Given k positive numbers a_1<a_2<a_3<...<a_k, and all integers greater > than a_k, we want to check whether this set {a_1, a_2, a_3,...a_k, a_k > + 1, a_k+2, ......} is closed under addition. > > Is there any easy way to do this? any functions that we could use in > Mathematica? > > Your help will be greatly appreciated. > > -- DrMajorBob at yahoo.com

**References**:**How to check whether an infinite set is closed under addition?***From:*Rex <aoirex@gmail.com>