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MBA, PHD
Phoniex
Jul-2007 - Jun-2012
Corportae Manager
ChevronTexaco Corporation
Feb-2009 - Nov-2016
Let D be the set of all calendar dates from 4/30/1789 to 9/25/2014.

Let P be the set of names of U.S. presidents.

Let F be the set of names of first ladies of the U.S.


Consider the following two functions press : D ⇒ P where  pres(d)  is the name of the president of the U.S. on date  d  (the incumbent on inauguration days, to avoid ambiguity) and  lady : P ⇒ F  where  lady(p)  is the name of the first lady of the U.S. during the presidency of president  P.


1. Can the composition  pres ° lady  be defined?  What about  lady °  pres ?
2. Which of the following functional inverses exist and which do not?
  pres-1, lady-1, (lady°pres)-1, (pres°lady)-1  (the -1 should be in superscript)
Thank you.
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Hel-----------lo -----------Sir-----------/Ma-----------dam----------- T-----------han-----------k Y-----------ou -----------for----------- us-----------ing----------- ou-----------r w-----------ebs-----------ite----------- an-----------d a-----------cqu-----------isi-----------tio-----------n o-----------f m-----------y p-----------ost-----------ed -----------sol-----------uti-----------on.----------- Pl-----------eas-----------e p-----------ing----------- me----------- on----------- ch-----------at -----------I a-----------m o-----------nli-----------ne -----------or -----------inb-----------ox -----------me -----------a m-----------ess-----------age----------- I -----------wil-----------l