Another very simple example would be a statement and its contrapositive. For instance: If Spot is a dog, then Spot is a mammal. If Spot is not a mammal, then Spot is not a dog. Or perhaps: If Spot is a dog, then Spot is not a bird. If Spot is a bird, then Spot is not a dog. Tom Mike Stay writes:
How about Ko? http://senseis.xmp.net/?Ko
On Mon, Mar 23, 2015 at 1:35 PM, Marc LeBrun <mlb@well.com> wrote:
="Guy Haworth" <g.haworth@reading.ac.uk> Are there simple examples of 'equivalence', T1 --> T2 and T2 --> T1 (setting up loop T1 --> T2 --> T1) that could be explained to school children?
Are these too trivial? A = B + C B = A - C C = A - B
Might one take the first as given, prove the second as T1 then show it implies the third as T2, and vice versa?
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
-- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun