Correction to notes distributed in class: page 4, third paragraph, second sentence should read "Since there are no formulas to the left of the turnstile, this gives us a proof of P->P from no assumptions, which means that P->P is a theorem of the system."
Getting started with LEGO is here.
Here is an annotated description of the reduction of 5+2.
Lego file containing examples of equational proofs.
Lego file containing the development of an integer square root function.
Lego file containing and/or tree definition.
Lego output from example proof discussed in class.
Lego file of examples.