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Expression of type Conditional

from the theory of proveit.numbers.numerals.decimals

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, Function, f, i, j
from proveit.core_expr_types import f_i_to_j
from proveit.logic import Equals
from proveit.numbers import Add, one, two
In [2]:
# build up the expression from sub-expressions
sub_expr1 = Add(i, two)
expr = Conditional(Equals([f_i_to_j], [Function(f, [i]), Function(f, [Add(i, one)]), Function(f, [sub_expr1])]), Equals(j, sub_expr1))
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())
\left\{\left(f\left(i\right), f\left(i + 1\right), \ldots, f\left(j\right)\right) = \left(f\left(i\right), f\left(i + 1\right), f\left(i + 2\right)\right) \textrm{ if } j = \left(i + 2\right)\right..
In [5]:
stored_expr.style_options()
namedescriptiondefaultcurrent valuerelated methods
condition_delimiter'comma' or 'and'commacomma('with_comma_delimiter', 'with_conjunction_delimiter')
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Conditionalvalue: 1
condition: 2
1Operationoperator: 4
operands: 3
2Operationoperator: 4
operands: 5
3ExprTuple6, 7
4Literal
5ExprTuple13, 19
6ExprTuple8
7ExprTuple9, 10, 11
8ExprRangelambda_map: 12
start_index: 27
end_index: 13
9Operationoperator: 20
operand: 27
10Operationoperator: 20
operand: 18
11Operationoperator: 20
operand: 19
12Lambdaparameter: 25
body: 17
13Variable
14ExprTuple27
15ExprTuple18
16ExprTuple19
17Operationoperator: 20
operand: 25
18Operationoperator: 23
operands: 22
19Operationoperator: 23
operands: 24
20Variable
21ExprTuple25
22ExprTuple27, 26
23Literal
24ExprTuple27, 28
25Variable
26Literal
27Variable
28Literal