You have a large number of $60^\circ$60° rhombi called "lozenges." Each lozenge has its edges marked with four distinct symbols drawn from an infinite alphabet. Lozenges may be rotated by $180^\circ$180° or reflected across either axis. A triple of lozenges forms a "hex" if the markings can be matched up in the following way:
_____B_____
/\ \
/ \ \
C E A
/ \ \
/ \____D_____\
\ / /
\ / /
A F C
\ / /
\/_____B____/,
where A,B B,C C,D D,E E,F F are distinct symbols. You wish to assemble all of your lozenges into hexes. Here are the conditions:
- You have access to a machine that can be programmed to produce arbitrary hexes; these hexes can be broken into new lozenges
- The total number of lozenges is a multiple of three
- For lozenge-type that you have, you have an even number of that type
Is it always possible to assemble all of your lozenges into hexes?