The similarities and differences among intuitionism, logicism and formalism can be traced back to Kant's thinking on the essence of mathematics in modern times.
Kant believes that arithmetic comes from the intuition of transcendental subject to the pure form of time, while geometry is the intuition to the pure form of space.
This is essentially a subjective and objective way of thinking.
Kant's thought was later inherited and developed by Husserl.
Husserl put forward the phenomenological reduction method from the consideration of "where is the number"
(Proportional function, linear function, quadratic function), unary quadratic equation, plane geometry, trigonometric function.
Factorization, set, logic