fix a bunch of missing cases
add a proof for list append assoc, equality automation and some techniques needed to be developped in order to make the proof process more unannoying
fix some bugs, now the proof can use let abrievation, it seems now it is necessary to implement a system to handle equations
fix the bugs of not displaying normalized proofs; invent a tactic called chain to handle multiple transitivity of equations
fix the weird catching error bug
fix a bug in unification; add a file for experimenting states
deal with observer
found a bug in comprehension
fix the bug in comprehension
fix a bug in comprehension, and finished my proof of observation, now I can proof 2+2=4git status yay
realize verified a simple real world program is real daunting
stateful property with stateful function
minor changes
add some examples and realize proof tactic can be powerful.