I offer this model insofar as it helps with communicating about the puzzle -http://bearlamp.com.au/a-model-of-arguments/and this onehttp://bearlamp.com.au/filter-on-the-way-in-filter-on-the-way-out/
I offer this model insofar as it helps with communicating about the puzzle -
http://bearlamp.com.au/a-model-of-arguments/
and this one
http://bearlamp.com.au/filter-on-the-way-in-filter-on-the-way-out/