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Expression of type Forall

from the theory of proveit.logic.equality

In [1]:
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, n, x
from proveit.core_expr_types import x_1_to_np1
from proveit.logic import Equals, Forall
from proveit.numbers import Add, NaturalPos, one
In [2]:
# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
expr = Forall(instance_param_or_params = [n], instance_expr = Forall(instance_param_or_params = [x_1_to_np1], instance_expr = Equals(IndexedVar(x, one), IndexedVar(x, Add(n, one))), condition = ExprRange(sub_expr1, Equals(IndexedVar(x, sub_expr1), IndexedVar(x, Add(sub_expr1, one))), one, n)), domain = NaturalPos)
expr:
In [3]:
# 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")
Passed sanity check: expr matches stored_expr
In [4]:
# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())
\forall_{n \in \mathbb{N}^+}~\left[\forall_{x_{1}, x_{2}, \ldots, x_{n + 1}~|~\left(x_{1} = x_{1 + 1}\right), \left(x_{2} = x_{2 + 1}\right), \ldots, \left(x_{n} = x_{n + 1}\right)}~\left(x_{1} = x_{n + 1}\right)\right]
In [5]:
stored_expr.style_options()
namedescriptiondefaultcurrent valuerelated methods
with_wrappingIf 'True', wrap the Expression after the parametersNoneNone/False('with_wrapping',)
condition_wrappingWrap 'before' or 'after' the condition (or None).NoneNone/False('with_wrap_after_condition', 'with_wrap_before_condition')
wrap_paramsIf 'True', wraps every two parameters AND wraps the Expression after the parametersNoneNone/False('with_params',)
justificationjustify to the 'left', 'center', or 'right' in the array cellscentercenter('with_justification',)
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Operationoperator: 7
operand: 2
1ExprTuple2
2Lambdaparameter: 33
body: 4
3ExprTuple33
4Conditionalvalue: 5
condition: 6
5Operationoperator: 7
operand: 11
6Operationoperator: 9
operands: 10
7Literal
8ExprTuple11
9Literal
10ExprTuple33, 12
11Lambdaparameters: 13
body: 14
12Literal
13ExprTuple15
14Conditionalvalue: 16
condition: 17
15ExprRangelambda_map: 18
start_index: 43
end_index: 28
16Operationoperator: 31
operands: 19
17Operationoperator: 20
operands: 21
18Lambdaparameter: 42
body: 34
19ExprTuple22, 23
20Literal
21ExprTuple24
22IndexedVarvariable: 37
index: 43
23IndexedVarvariable: 37
index: 28
24ExprRangelambda_map: 27
start_index: 43
end_index: 33
25ExprTuple43
26ExprTuple28
27Lambdaparameter: 42
body: 29
28Operationoperator: 40
operands: 30
29Operationoperator: 31
operands: 32
30ExprTuple33, 43
31Literal
32ExprTuple34, 35
33Variable
34IndexedVarvariable: 37
index: 42
35IndexedVarvariable: 37
index: 39
36ExprTuple42
37Variable
38ExprTuple39
39Operationoperator: 40
operands: 41
40Literal
41ExprTuple42, 43
42Variable
43Literal