Syntactical completeness is only concerned with syntactics.The classical preposition logic systems with the rule of substitution are syntactically complete, while the ones without the rule are not.

• 摘要语法完全性仅与一个形式系统的语法构造相关，经典命题逻辑的有代入规则的系统是语法完全的，无代入规则的系统不是语法完全的。