"\ln(constant) × variable" simplifies to "NaN"

[AlexEdgcomb]

Description

The .simplify() method incorrectly returns NaN when simplifying expressions containing \ln(constant) × variable or \log(constant) × variable.

Impacts symbolic computation involving logarithms multiplied with variables, preventing equivalence checking and mathematical operations.

Steps to Reproduce

1. Go to https://codepen.io/alexedgcomb/pen/jEWvByB?editors=1001 (Compute Engine version: 0.30.2)

Actual Result

Console has:

"Parsed:" "x\ln(8)"
"Simplified:" "\operatorname{NaN}"
"Simplified JSON:" "NaN"
"Simplified:" "\operatorname{NaN}"
"Simplified:" "(2x+9)\times8^{x^2+9x}"

All expressions containing \ln(constant) × variable become NaN during simplification. The pattern fails for any constant: \ln(2), \ln(8), \ln(10), etc. Notably, expressions WITHOUT \ln simplify correctly (Example 3).

Expected Result

Console have:

"Parsed": "x\ln(8)"
"Simplified": "x\ln(8)"  OR  "3x\ln(2)"
"Simplified JSON": ["Multiply", "x", ["Ln", 8]]  OR equivalent
"Simplified": "(2x+9)\ln(8)\times8^{x^2+9x}"  OR simplified form
"Simplified": "(2x+9)\times8^{x^2+9x}"

The expression \ln(constant) × variable is mathematically valid and should either:

1. Remain as-is during simplification
2. Be simplified using logarithm laws (e.g., ln(8) = 3ln(2))

Mathematical Context:

• \ln(8) alone evaluates correctly to 2.0794...
• \ln(8) × x is a valid symbolic expression
• Other symbolic math systems (SymPy, Mathematica, Maple) preserve this form or simplify using logarithm properties, never returning NaN

Environment

Regression:

• Worked: 0.20.2 - 0.25.0
• Broken: 0.26.0 - 0.30.2

Perhaps related issue: #227 (Canonicalization over-simplifies division) also involves the canonicalization/simplification process producing incorrect results for mathematically valid expressions.