Question 933195
all subsets for the set {6,9} are: S={ }, {6}, {9}, {6,9}

{{{S}}} is a {{{proper}}} subset of a set {{{A}}} if {{{S}}} is a subset of {{{A}}} but {{{S<>A}}}. 
Therefore, the only set that is {{{not}}} a {{{proper}}} subset of {{{A}}} is the set {{{A}}} {{{itself}}}. In other words, only subset {6,9} is not a {{{proper}}} subset.