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In [1]:
import proveit
from proveit import defaults
from proveit import x, y
from proveit.logic.equality  import not_equals_def
theory = proveit.Theory() # the theorem's theory
In [2]:
%proving fold_not_equals
With these allowed/disallowed theorem/theory presumptions (e.g., to avoid circular dependencies), we begin our proof of
fold_not_equals:
(see dependencies)
fold_not_equals may now be readily provable (assuming required theorems are usable).  Simply execute "%qed".
In [3]:
defaults.assumptions = fold_not_equals.conditions
defaults.assumptions:
In [4]:
not_equals_def
In [5]:
not_equals_def.instantiate({x:x, y:y}).derive_left_via_equality()
In [6]:
%qed
proveit.logic.equality.fold_not_equals has been proven.
Out[6]:
 step typerequirementsstatement
0generalization1  ⊢  
1instantiation2, 3  ⊢  
  :
2axiom  ⊢  
 proveit.logic.booleans.eq_true_elim
3instantiation4, 5*  ⊢  
  : , :
4axiom  ⊢  
 proveit.logic.equality.not_equals_def
5instantiation6, 7  ⊢  
  :
6axiom  ⊢  
 proveit.logic.booleans.eq_true_intro
7assumption  ⊢  
*equality replacement requirements