Expression of type Len

from the theory of proveit.numbers.numerals.decimals

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 ExprRange, Variable
from proveit.core_expr_types import Len
from proveit.numbers import eight, five, four, nine, one, seven, six, three, two

# build up the expression from sub-expressions
expr = Len(operands = [three, eight, six, seven, four, ExprRange(Variable("_a", latex_format = r"{_{-}a}"), nine, one, four), five, seven, two])

expr:

# 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

# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())

|\left(3, 8, 6, 7, 4,9, 9, ..1 \times.., 9, 5, 7, 2\right)|

stored_expr.style_options()

name	description	default	current value	related methods
operation	'infix' or 'function' style formatting	infix	infix
wrap_positions	position(s) at which wrapping is to occur; '2 n - 1' is after the nth operand, '2 n' is after the nth operation.	()	()	('with_wrapping_at', 'with_wrap_before_operator', 'with_wrap_after_operator', 'without_wrapping', 'wrap_positions')
justification	if any wrap positions are set, justify to the 'left', 'center', or 'right'	center	center	('with_justification',)

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Operation	operator: 1 operands: 2
1	Literal
2	ExprTuple	3, 4, 5, 8, 12, 6, 7, 8, 9
3	Literal
4	Literal
5	Literal
6	ExprRange	lambda_map: 10 start_index: 11 end_index: 12
7	Literal
8	Literal
9	Literal
10	Lambda	parameter: 15 body: 14
11	Literal
12	Literal
13	ExprTuple	15
14	Literal
15	Variable