[ot][spam]gpt-4 completions

Undescribed Horrific Abuse, One Victim & Survivor of Many gmkarl at gmail.com
Fri Oct 13 16:27:27 PDT 2023


GPT-4

User
Use codegolf and other techniques to write incredibly short python
classes for symbolic algebra.

ChatGPT
Creating a concise Python class for symbolic algebra while also
following the principles of "code golf" (writing code using the fewest
characters possible) can be quite fun! Here’s a super-minimal class
that could create symbolic variables and handle basic addition and
multiplication:

```python
class S(str):
    def __add__(a,b):return S('('+a+'+'+b+')')
    def __mul__(a,b):return S('('+a+'*'+b+')')
```

Example usage:
```python
x,y=S('x'),S('y')
expr=x+y*x
print(expr) # (x+(y*x))
```

Explanation:

- `class S(str)`: Define a class `S` which inherits from `str`.
- `def __add__(a,b):`: Define addition for instances `a` and `b`.
- `return S('('+a+'+'+b+')')`: Return a new `S` which is a string
concatenation of `a` and `b` with an added "+" in between and
surrounded by parentheses.
- Multiplication is defined similarly.

This is about as short as we could reasonably make it while still
having it be somewhat usable. It handles the representation of basic
algebraic expressions in symbolic form with addition and
multiplication. However, real symbolic algebra libraries have many
more features like simplification, substitution, solving equations,
etc. Note that this code does not evaluate expressions in any way,
just represents them as strings in a somewhat structured way.

Do keep in mind that this code is not at all optimal, nor is it
particularly usable for any serious application. In production or any
serious application, you would typically use a library like SymPy for
symbolic algebra in Python, which has been optimized and tested for
robustness and accuracy.

User
Update the class to handle all python operators by introspection. Map
inverses for use by automated solvers. Continue to use code golf
techniques.

ChatGPT
Handling all operators with introspection and mapping inverses while
maintaining code-golf-style brevity is a challenging and fun task!
Here is a very compact implementation that uses Python's `__add__`,
`__sub__`, `__mul__`, `__truediv__`, `__pow__`, and their respective
inverse operations:

```python
class S(str):
    def b(m,a,b):return S('('+a+m+b+')')
    def __add__(a,b):return a.b('+',a,b)
    def __sub__(a,b):return a.b('-',a,b)
    def __mul__(a,b):return a.b('*',a,b)
    def __truediv__(a,b):return a.b('/',a,b)
    def __pow__(a,b):return a.b('**',a,b)
```

This class now supports basic operations (addition, subtraction,
multiplication, division, and power). To use inverse mappings, which
will be needed for automated solvers, you would require more complex
functionality and potentially lose the brevity of the code. But let's
try something, keeping it as short as possible:

```python
class S(str):
    def b(m,a,b):return S('('+a+m+b+')')
    def __add__(a,b):return a.b('+',a,b)
    def __sub__(a,b):return a.b('-',a,b)
    def __mul__(a,b):return a.b('*',a,b)
    def __truediv__(a,b):return a.b('/',a,b)
    def __pow__(a,b):return a.b('**',a,b)
    def __neg__(a):return S('-'+a)
    i={'-':'__sub__','+':'__add__','*':'__mul__','/':'__truediv__','**':'__pow__'}
```

Here, `i` is a dictionary that maps operators to their corresponding
"dunder" method names, which could be useful for implementing solvers
by calling the inverse operation using `getattr(obj, method_name)`
syntax.

Keep in mind that these classes are too minimal and non-functional for
practical applications involving symbolic algebra and automated
solvers. They serve more as a fun and conceptual demonstration of how
one might approach the problem in a code-golf context. The full
functionality of symbolic algebra typically involves much more
complexity in handling, simplifying, and solving expressions, which
cannot be achieved with ultra-short code.


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