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Expression of type Forall

from the theory of proveit.numbers.functions

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 Conditional, ConditionalSet, i, j
from proveit.logic import Equals, Forall, NotEquals
from proveit.numbers import KroneckerDelta, one, zero
In [2]:
# build up the expression from sub-expressions
expr = Forall(instance_param_or_params = [i, j], instance_expr = Equals(KroneckerDelta(i, j), ConditionalSet(Conditional(one, Equals(i, j)), Conditional(zero, NotEquals(i, j)))))
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_{i, j}~\left(\delta_{i, j} = \left\{\begin{array}{ccc}1 \textrm{ if } i = j \\ 0 \textrm{ if } i \neq j\end{array}\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: 1
operand: 3
1Literal
2ExprTuple3
3Lambdaparameters: 19
body: 4
4Operationoperator: 17
operands: 5
5ExprTuple6, 7
6Operationoperator: 8
operands: 19
7Operationoperator: 9
operands: 10
8Literal
9Literal
10ExprTuple11, 12
11Conditionalvalue: 13
condition: 14
12Conditionalvalue: 15
condition: 16
13Literal
14Operationoperator: 17
operands: 19
15Literal
16Operationoperator: 18
operands: 19
17Literal
18Literal
19ExprTuple20, 21
20Variable
21Variable