- #1
SithsNGiggles
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This is the conclusion of a proof (any subset of a finite set is finite, which was worked on in this thread: https://www.physicsforums.com/showthread.php?t=592636) I recently presented, but I was told that I couldn't immediately make it:
[itex]S = T \cup (S \setminus T)[/itex] (where T is a subset of S)
[itex]f(S) = g(T) \cup h(S \setminus T)[/itex]
I showed earlier in the proof that [itex]f(S) = S[/itex] and [itex]h(S \setminus T) = S \setminus T[/itex].
I say that it immediately follows that [itex]g(T) = T[/itex] because
[itex]f(x) = \left\{
\begin{array}{l}
g(x) & : x \in T\\
h(x) & : x \in S \setminus T
\end{array}
\right.[/itex]
which shows that [itex]g(T) \cap h(S \setminus T) = \emptyset[/itex].
What could I be missing? Thanks for any help.
[itex]S = T \cup (S \setminus T)[/itex] (where T is a subset of S)
[itex]f(S) = g(T) \cup h(S \setminus T)[/itex]
I showed earlier in the proof that [itex]f(S) = S[/itex] and [itex]h(S \setminus T) = S \setminus T[/itex].
I say that it immediately follows that [itex]g(T) = T[/itex] because
[itex]f(x) = \left\{
\begin{array}{l}
g(x) & : x \in T\\
h(x) & : x \in S \setminus T
\end{array}
\right.[/itex]
which shows that [itex]g(T) \cap h(S \setminus T) = \emptyset[/itex].
What could I be missing? Thanks for any help.