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Expression of type Lambda

from the theory of proveit.linear_algebra.scalar_multiplication

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, ExprRange, IndexedVar, Lambda, V, Variable, n, x
from proveit.core_expr_types import x_1_to_n
from proveit.linear_algebra import lin_comb_axn
from proveit.logic import And, InSet
from proveit.numbers import one
In [2]:
# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
expr = Lambda([x_1_to_n], Conditional(InSet(lin_comb_axn, V), And(ExprRange(sub_expr1, InSet(IndexedVar(x, sub_expr1), V), one, n))))
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(x_{1}, x_{2}, \ldots, x_{n}\right) \mapsto \left\{\left(\left(a_{1} \cdot x_{1}\right) +  \left(a_{2} \cdot x_{2}\right) +  \ldots +  \left(a_{n} \cdot x_{n}\right)\right) \in V \textrm{ if } \left(x_{1} \in V\right) \land  \left(x_{2} \in V\right) \land  \ldots \land  \left(x_{n} \in V\right)\right..
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameters: 1
body: 2
1ExprTuple3
2Conditionalvalue: 4
condition: 5
3ExprRangelambda_map: 6
start_index: 18
end_index: 19
4Operationoperator: 20
operands: 7
5Operationoperator: 8
operands: 9
6Lambdaparameter: 31
body: 27
7ExprTuple10, 23
8Literal
9ExprTuple11
10Operationoperator: 12
operands: 13
11ExprRangelambda_map: 14
start_index: 18
end_index: 19
12Literal
13ExprTuple15
14Lambdaparameter: 31
body: 16
15ExprRangelambda_map: 17
start_index: 18
end_index: 19
16Operationoperator: 20
operands: 21
17Lambdaparameter: 31
body: 22
18Literal
19Variable
20Literal
21ExprTuple27, 23
22Operationoperator: 24
operands: 25
23Variable
24Literal
25ExprTuple26, 27
26IndexedVarvariable: 28
index: 31
27IndexedVarvariable: 29
index: 31
28Variable
29Variable
30ExprTuple31
31Variable