import proveit
# Automation is not needed when building an expression:
proveit.defaults.automation = False # This will speed things up.
proveit.defaults.inline_pngs = False # Makes files smaller.
%load_expr # Load the stored expression as 'stored_expr'
# import Expression classes needed to build the expression
from proveit import ExprRange, IndexedVar, Variable, a, b, c, n
from proveit.logic import Equals
from proveit.numbers import Add, Neg, one, subtract, three, two
# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
sub_expr2 = IndexedVar(a, sub_expr1)
sub_expr3 = Neg(c)
expr = Equals(Add(Add(ExprRange(sub_expr1, sub_expr2, three, n), b), subtract(sub_expr3, Add(ExprRange(sub_expr1, sub_expr2, one, subtract(n, two))))), Add(IndexedVar(a, subtract(n, one)), IndexedVar(a, n), b, sub_expr3, Neg(IndexedVar(a, one)), Neg(IndexedVar(a, two))))
# check that the built expression is the same as the stored expression
assert expr == stored_expr
assert expr._style_id == stored_expr._style_id
print("Passed sanity check: expr matches stored_expr")
# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())
stored_expr.style_options()
# display the expression information
stored_expr.expr_info()