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Expression of type Lambda

from the theory of proveit.core_expr_types.lambda_maps

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 Composition, Function, Lambda, f, fx, g, gy, gz, x, y, z
from proveit.logic import Equals
In [2]:
# build up the expression from sub-expressions
expr = Lambda([f, g], Equals(Composition(Lambda(x, fx), Lambda(y, gy)), Lambda(z, Function(f, [gz]))))
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(f, g\right) \mapsto \left(\left(\left[x \mapsto f\left(x\right)\right] \circ \left[y \mapsto g\left(y\right)\right]\right) = \left[z \mapsto f\left(g\left(z\right)\right)\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
1ExprTuple16, 19
2Operationoperator: 3
operands: 4
3Literal
4ExprTuple5, 6
5Operationoperator: 7
operands: 8
6Lambdaparameter: 23
body: 9
7Literal
8ExprTuple10, 11
9Operationoperator: 16
operand: 15
10Lambdaparameter: 21
body: 13
11Lambdaparameter: 22
body: 14
12ExprTuple15
13Operationoperator: 16
operand: 21
14Operationoperator: 19
operand: 22
15Operationoperator: 19
operand: 23
16Variable
17ExprTuple21
18ExprTuple22
19Variable
20ExprTuple23
21Variable
22Variable
23Variable