Support multi-line PARI formulas for multiple functions

[Copilot]

PARI/GP formula generation now outputs multiple functions on separate lines, matching the existing LEAN formatter behavior.

Changes

• src/form/pari.cpp: Modified PariFormula::toString() to detect multiple functions via FormulaUtil::getDefinitions() and format them with newline separators instead of semicolons
• tests/formula/pari-function.txt: Updated test expectations for A000058 and A001715 to reflect multi-line output format

Example

Before:

(a(n) = b(n)+1); (b(n) = if(n==0,1,local(l1=b(n-1)); l1*(l1+1)))

After:

a(n) = b(n)+1
b(n) = if(n==0,1,local(l1=b(n-1)); l1*(l1+1))

Single-function formulas remain unchanged on a single line.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Multi-line PARI formulas</issue_title>
<issue_description>Similarly to the LEAN formula generation, it would be nice to split the generated formula code for PARI/GP into multiple lines if there are multiple functions.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Multi-line PARI formulas #581

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.