code: def p_blocking_substitution(self, p):
          'blocking_substitution : delays lvalue EQUALS delays rvalue SEMICOLON'
          p[0] = BlockingSubstitution(p[2], p[5], p[1], p[4], lineno=p.lineno(2))
          p.set_lineno(0, p.lineno(2)f p_blocking_substitution(self, p):
          'blocking_substitution : delays lvalue EQUALS delays rvalue SEMICOLON'
          p[0] = BlockingSubstitution(p[2], p[5], p[1], p[4], lineno=p.lineno(2))
          p.set_lineno(0, p.lineno(2))
docs: blocking_substitution : delays lvalue EQUALS delays rvalue SEMICOLON