Tobin tried to define a translation. Point AAA maps to point A'A
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A, prime.
Every point PPP maps to point P'P
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P, prime such that \overline{PP'}
PP
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start overline, P, P, prime, end overline has the same length as \overline{AA'}
AA
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start overline, A, A, prime, end overline.
What mistake did Tobin make in her definition of a translation?