Update app.py

app.py

@@ -18,7 +18,9 @@ def clean_latex(latex):
     latex = latex.replace('\\ ', '')
     latex = latex.replace('\\\\', '\\')
     latex = re.sub(r'\\[ \t\n\r\f\v]*', '', latex)
+
     latex = re.sub(r'\\([+\-=])', r'\1', latex)
+
     replacements = {
         r'\\chi': 'x', r'chi': 'x',
         r'\\xi': 'x', r'xi': 'x',
@@ -32,23 +34,32 @@ def clean_latex(latex):
     }
     for wrong, correct in replacements.items():
         latex = re.sub(wrong, correct, latex)
-    latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[XxYyZz]\s*\}?', lambda m: m.group(0)[-2], latex)
-    latex = latex.replace('cal x', 'x').replace('mathcal x', 'x')
+
+    latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Xx]\s*\}?', 'x', latex)
+    latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Yy]\s*\}?', 'y', latex)
+    latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Zz]\s*\}?', 'z', latex)
+
+    latex = latex.replace('cal x', 'x').replace('cal X', 'x')
+    latex = latex.replace('mathcal x', 'x').replace('mathcal X', 'x')
+
     latex = latex.replace('{', '').replace('}', '')
     latex = latex.strip().rstrip(',.')
     latex = re.sub(r'(?<![a-zA-Z0-9])e(?![a-zA-Z0-9])', 'E', latex)
+
     latex = re.sub(r'(\d)([a-zA-Z])', r'\1*\2', latex)
     latex = re.sub(r'(\d+)\s*i', r'\1*I', latex)
     latex = re.sub(r'(?<![a-zA-Z0-9])i(?![a-zA-Z0-9])', 'I', latex)
     latex = re.sub(r'\(([^()]+?)\)\s*([a-zA-Z](\^\d+)?)', r'(\1)*\2', latex)
+
     latex = latex.replace(r'\cdot', '*')
-    latex = latex.replace('−', '-')  # Unicode minus
+    latex = latex.replace('−', '-')
     latex = re.sub(r'[^\w\s^=+*\-().]', '', latex)
+
     if '=' not in latex:
         latex += '=0'
+
     return latex
 
-# Fallback to external LLM microservice
 def request_llm_fallback(bad_latex, llm_url):
     pre_cleaned = re.sub(
         r'(\\!?pm|\\not=?|\\!|\\L|\\perp|\\bar|\\Sigma|\\boldmath|G|L(?=\^))', '', bad_latex
@@ -61,7 +72,6 @@ def request_llm_fallback(bad_latex, llm_url):
         print(f"LLM fallback failed: {e}")
     return pre_cleaned
 
-# Request human-style explanation
 def request_llm_explanation(latex, llm_url):
     try:
         response = requests.post(f"{llm_url}/explain", json={"prompt": latex})
@@ -72,7 +82,6 @@ def request_llm_explanation(latex, llm_url):
     except Exception as e:
         return f"❌ LLM explanation error: {e}"
 
-# Main solver
 def solve_polynomial(image, llm_url):
     try:
         img = preprocess_handwritten_image(image)
@@ -85,21 +94,14 @@ def solve_polynomial(image, llm_url):
 
         try:
             expr = parse_latex(cleaned_latex)
-
-            # ✅ Replace pi and e by name
-            for symbol in expr.free_symbols:
-                if str(symbol) == 'pi':
-                    expr = expr.subs(symbol, sp.Float(3.1416))
-                elif str(symbol) == 'e':
-                    expr = expr.subs(symbol, sp.Float(2.7183))
+            # ✅ Force numeric substitution even if pi/E not in free_symbols
+            expr = expr.subs(sp.pi, sp.Float(3.1416)).subs(sp.E, sp.Float(2.7183))
 
             if not isinstance(expr, sp.Equality):
                 raise ValueError("Expression is not an equation.")
-
             lhs_minus_rhs = expr.lhs - expr.rhs
             if not lhs_minus_rhs.is_polynomial():
                 raise ValueError("Expression is not a polynomial.")
-
             junk_symbols = {"pm", "cdot", "mathrm", "boldmath", "bar", "L"}
             symbols = {str(s) for s in expr.free_symbols}
             if symbols & junk_symbols:
@@ -109,13 +111,8 @@ def solve_polynomial(image, llm_url):
             cleaned_latex = clean_latex(fixed_latex)
             try:
                 expr = parse_latex(cleaned_latex)
-
-                # ✅ Repeat fix in fallback too
-                for symbol in expr.free_symbols:
-                    if str(symbol) == 'pi':
-                        expr = expr.subs(symbol, sp.Float(3.1416))
-                    elif str(symbol) == 'e':
-                        expr = expr.subs(symbol, sp.Float(2.7183))
+                # ✅ Apply again after fallback
+                expr = expr.subs(sp.pi, sp.Float(3.1416)).subs(sp.E, sp.Float(2.7183))
 
                 if not isinstance(expr, sp.Equality):
                     raise ValueError("Expression is not an equation.")
@@ -173,6 +170,7 @@ def solve_polynomial(image, llm_url):
     except Exception as e:
         return f"❌ **Error**: {str(e)}", "", ""
 
+
 # Gradio UI
 with gr.Blocks() as demo:
     llm_url = gr.Textbox(label="🔗 Enter LLM Microservice URL (from Colab)", placeholder="https://xxxx.ngrok-free.app")