slight improvement for XSB error message
slight improvement for XSB error message

jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico,jbalint/banshee-sympatico