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Expression of type Lambda

from the theory of proveit.logic.sets.functions.injections

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 A, B, Lambda, a, b, f, fa, fb
from proveit.logic import And, Equals, Forall, Functions, InSet, Injections, NotEquals
In [2]:
# build up the expression from sub-expressions
expr = Lambda(f, Equals(InSet(f, Injections(A, B)), And(InSet(f, Functions(A, B)), Forall(instance_param_or_params = [a, b], instance_expr = NotEquals(fa, fb), domain = A, condition = NotEquals(a, b)))).with_wrapping_at(2))
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())
f \mapsto \left(\begin{array}{c} \begin{array}{l} \left(f \in \left[A \xrightarrow[]{\text{1-to-1}} B\right]\right) =  \\ \left(\left(f \in \left[A \rightarrow B\right]\right) \land \left[\forall_{a, b \in A~|~a \neq b}~\left(f\left(a\right) \neq f\left(b\right)\right)\right]\right) \end{array} \end{array}\right)
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameter: 33
body: 2
1ExprTuple33
2Operationoperator: 3
operands: 4
3Literal
4ExprTuple5, 6
5Operationoperator: 36
operands: 7
6Operationoperator: 25
operands: 8
7ExprTuple33, 9
8ExprTuple10, 11
9Operationoperator: 12
operands: 19
10Operationoperator: 36
operands: 13
11Operationoperator: 14
operand: 17
12Literal
13ExprTuple33, 16
14Literal
15ExprTuple17
16Operationoperator: 18
operands: 19
17Lambdaparameters: 39
body: 20
18Literal
19ExprTuple40, 21
20Conditionalvalue: 22
condition: 23
21Variable
22Operationoperator: 38
operands: 24
23Operationoperator: 25
operands: 26
24ExprTuple27, 28
25Literal
26ExprTuple29, 30, 31
27Operationoperator: 33
operand: 41
28Operationoperator: 33
operand: 42
29Operationoperator: 36
operands: 35
30Operationoperator: 36
operands: 37
31Operationoperator: 38
operands: 39
32ExprTuple41
33Variable
34ExprTuple42
35ExprTuple41, 40
36Literal
37ExprTuple42, 40
38Literal
39ExprTuple41, 42
40Variable
41Variable
42Variable