Upd.

SylvyKernel/kernel.py

@@ -44,7 +44,7 @@ class SVG(object):
 
   def _repr_svg_(self):
     return self.text
-
+ 
 class SylvyKernel(MetaKernel):
   implementation = 'sylvy'
   implementation_version = '0.1'
@@ -68,12 +68,15 @@ class SylvyKernel(MetaKernel):
 
   _engine = None
 
+  def restart_kernel(self):
+    self.do_shutdown(True)
+
   def do_shutdown(self, restart):
     if self._engine:
       self._engine.api('discard')
 
       self._engine = None
-
+    
   def do_execute_direct(self, code):
     if not code.strip():
       return