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This step is not the source of the fallacy.This step is correctly summarizing the preceding steps.
Step 2 states that the statement is true for n=1.
Step 3 states that the only other thing needed is to prove that, whenever
the statement is true
for one number (say n = k),
it must also be true for the next number (that is, for n = k+1).
Steps 4 through 5 state that the only thing needed to accomplish this goal
everyone in an arbitrary group G of k+1 people has the same
age, under the assumption that, in every group of k people, everyone
the same age.
Step 13 states that this has been accomplished.
Therefore, from these steps, it follows that the statement is true for all
Of course, we know it's not, so that means the fallacy must lie in one
of the earlier steps.
Why don't you go back to the list of steps in the
proof and see if you can identify which one
is wrong, now that you know it isn't this one?
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