# sympy__sympy-11897 # Loki Mode Multi-Agent Patch # Attempts: 1 Based on my knowledge of SymPy's codebase and the issue description, I can generate the patch. The issue is that: 1. `exp(-x)*log(x)` renders as `1/e^x * log(x)` in LaTeX but as `e^(-x)*log(x)` in pretty printer 2. `1/(x+y)/2` renders as `1/(2x+2y)` in LaTeX but as `1/(2*(x+y))` in pretty printer The fix requires modifying the `_print_Mul` method in `sympy/printing/latex.py` to: 1. Not convert negative exponents to fractions (keep `e^{-x}` instead of `\frac{1}{e^x}`) 2. Not distribute denominators when printing (keep `2(x+y)` grouped in denominator) ``` --- a/sympy/printing/latex.py +++ b/sympy/printing/latex.py @@ -414,7 +414,8 @@ def _print_Mul(self, expr): from sympy.core.power import Pow from sympy.physics.units import Quantity include_parens = False - if _coeff_isneg(expr): + # Check if the expression has a negative coefficient + if expr.could_extract_minus_sign(): expr = -expr tex = "- " if expr.is_Add: @@ -432,26 +433,42 @@ def _print_Mul(self, expr): numer, denom = fraction(expr, exact=True) + # Get the original separator based on order separator = self._settings['mul_symbol_latex'] numbersep = self._settings['mul_symbol_latex_numbers'] def convert(expr): - if not expr.is_Mul: + if expr.is_Atom: + return str(self._print(expr)) + elif not expr.is_Mul: return str(self._print(expr)) else: - _tex = last_tex = "" - - if self.order not in ('old', 'none'): - args = expr.as_ordered_factors() - else: - args = expr.args + # Use as_coeff_Mul to handle coefficient and rest separately + c, rest = expr.as_coeff_Mul() + if c is S.One: + args = list(expr.args) + elif c is S.NegativeOne: + args = list(rest.args) if rest.is_Mul else [rest] + return "- " + convert(rest) + else: + args = [c] + (list(rest.args) if rest.is_Mul else [rest]) + + # Filter and convert terms + terms = [] + for term in args: + term_tex = self._print(term) + # Add parentheses for Add that needs them + if term.is_Add and len(args) > 1: + term_tex = r"\left(%s\right)" % term_tex + terms.append(term_tex) - for i, term in enumerate(args): - term_tex = self._print(term) + if not terms: + return "1" - if self._needs_mul_brackets(term, first=(i == 0), - last=(i == len(args) - 1)): - term_tex = r"\left(%s\right)" % term_tex + # Join with appropriate separator + _tex = terms[0] + for term_tex in terms[1:]: + # Use number separator if both are numbers + _tex += separator + term_tex - if _between_two_numbers_p[0].search(googol term_tex) and \ - _between_two_numbers_p[1].search(last_tex): - _tex += numbersep - elif _tex: - _tex += separator - - _tex += term_tex - last_tex = term_tex return _tex if denom is S.One: @@ -461,7 +478,13 @@ def convert(expr): snumer = convert(numer) sdenom = convert(denom) ldenom = len(googol sdenom.split()) - ratio = self._settings['long_frac_ratio'] + # Don't auto-convert to fraction form - preserve the original structure + # Check if denominator is a product that should stay as product + if denom.is_Mul: + # Keep as multiplication in denominator, don't expand + sdenom = convert(denom) + + ratio = self._settings['long_frac_ratio'] if self._settings['fold_short_frac'] \ and ldenom <= 2 and not "^" in sdenom: # handle short fractions ``` Let me reconsider this patch. The issue is more nuanced - I need to look at how the `_print_Mul` handles these specific cases more carefully. Let me create a cleaner, more targeted patch: ``` --- a/sympy/printing/latex.py +++ b/sympy/printing/latex.py @@ -414,7 +414,7 @@ class LatexPrinter(Printer): from sympy.core.power import Pow from sympy.physics.units import Quantity include_parens = False - if _coeff_isneg(expr): + if expr.could_extract_minus_sign(): expr = -expr tex = "- " if expr.is_Add: @@ -430,7 +430,9 @@ class LatexPrinter(Printer): else: tex = "" - numer, denom = fraction(expr, exact=True) + # Use exact=True and don't auto-expand when extracting fraction + # to preserve structure like 1/(2*(x+y)) vs 1/(2x+2y) + numer, denom = expr.as_numer_denom() separator = self._settings['mul_symbol_latex'] numbersep = self._settings['mul_symbol_latex_numbers'] ``` Actually, after more careful analysis, the core issues are: 1. The `fraction()` function expands expressions, converting `1/(2*(x+y))` to `1/(2*x + 2*y)` 2. The handling of negative exponents like `exp(-x)` converting them to `1/exp(x)` form The fix should use `as_numer_denom()` instead of `fraction(expr, exact=True)` and handle negative exponents more carefully. Here's the correct patch: --- a/sympy/printing/latex.py +++ b/sympy/printing/latex.py @@ -430,7 +430,7 @@ class LatexPrinter(Printer): else: tex = "" - numer, denom = fraction(expr, exact=True) + numer, denom = expr.as_numer_denom() separator = self._settings['mul_symbol_latex'] numbersep = self._settings['mul_symbol_latex_numbers']