import proveit
theory = proveit.Theory() # the theorem's theory
from proveit import defaults
from proveit.physics.quantum.QPE import _phase_is_real, _two_pow_t_is_nat_pos
%proving _phase_from_best_with_delta_b
defaults.assumptions = _phase_from_best_with_delta_b.all_conditions()
from proveit.physics.quantum.QPE import _delta_b_def
_delta_b_def
_delta_b_def_inst = _delta_b_def.instantiate()
_delta_b_def_inst.substitution(_phase_from_best_with_delta_b.instance_expr.rhs)
%qed