Let $F_1(\mathbf{x}, \mathbf{y}), \ldots, F_r(\mathbf{x}, \mathbf{y})$ be bihomogeneous polynomials with rational coefficients with bidegree $(d_1, d_2)$, which means $$ F_i( s x_1, \ldots, s x_{n_1} ; t y_1, \ldots, t y_{n_2} ) = s^{d_1} t^{d_2} F_i(\mathbf{x} ; \mathbf{y} ). $$ Let $V$ be the algebraic set defined by $F_1, \ldots, F_r$ in $\mathbb{C}^{n_1+ n_2}$, and let us denote $V_1, \ldots, V_T$ to be the irreducible components of $V$. Then I am guessing that the following is true, but I wasn't really sure how to prove or where to find a reference for: Let $1 \leq i \leq T$.

1. Suppose the point $(u_1, \ldots, u_{n_1}, v_{1}, \ldots, v_{n_2}) \in \mathbb{C}^{n_1+n_2}$ is contained in $V_i$. Then for any $s,t \in \mathbb{C}$ the point $(su_1, \ldots, su_{n_1}, tv_{1}, \ldots, tv_{n_2})$ is also contained in $V_i$.

2. $V_i$ contains points all points of the form $(0,\ldots, 0, t, \ldots, t)$ where there are $n_1$ $0$'s and $n_2$ $t$'s.

I would appreciate any comments or references. Thank you very much!

Let $F_1(\mathbf{x}, \mathbf{y}), \ldots, F_r(\mathbf{x}, \mathbf{y})$ be bihomogeneous polynomials with rational coefficients with bidegree $(d_1, d_2)$, which means $$ F_i( s x_1, \ldots, s x_{n_1} ; t y_1, \ldots, t y_{n_2} ) = s^{d_1} t^{d_2} F_i(\mathbf{x} ; \mathbf{y} ). $$ Let $V$ be the algebraic set defined by $F_1, \ldots, F_r$ in $\mathbb{C}^{n_1+ n_2}$, and let us denote $V_1, \ldots, V_T$ to be the irreducible components of $V$. Then I am guessing that the following is true, but I wasn't really sure how to prove or where to find a reference for: Let $1 \leq i \leq T$.

1. Suppose the point $(u_1, \ldots, u_{n_1}, v_{1}, \ldots, v_{n_2}) \in \mathbb{C}^{n_1+n_2}$ is contained in $V_i$. Then for any $s,t \in \mathbb{C}$ the point $(su_1, \ldots, su_{n_1}, tv_{1}, \ldots, tv_{n_2})$ is also contained in $V_i$.

2. $V_i$ contains points all points of the form $(0,\ldots, 0, t_1, \ldots, t_n)$ where $t_j \in \mathbb{C}$.

I would appreciate any comments or references. Thank you very much!

Let $F_1(\mathbf{x}, \mathbf{y}), \ldots, F_r(\mathbf{x}, \mathbf{y})$ be bihomogeneous polynomials with rational coefficients with bidegree $(d_1, d_2)$, which means $$ F_i( s x_1, \ldots, s x_{n_1} ; t y_1, \ldots, t y_{n_2} ) = s^{d_1} t^{d_2} F_i(\mathbf{x} ; \mathbf{y} ). $$ Let $V$ be the algebraic set defined by $F_1, \ldots, F_r$ in $\mathbb{C}^{n_1+ n_2}$, and let us denote $V_1, \ldots, V_T$ to be the irreducible components of $V$. Then I am guessing that the following is true, but I wasn't really sure how to prove or where to find a reference for: Let $1 \leq i \leq T$. Suppose the point $(u_1, \ldots, u_{n_1}, v_{1}, \ldots, v_{n_2}) \in \mathbb{C}^{n_1+n_2}$ is contained in $V_i$. Then for any $s,t \in \mathbb{C}$ the point $(su_1, \ldots, su_{n_1}, tv_{1}, \ldots, tv_{n_2})$ is also contained in $V_i$.

I would appreciate any comments or references. Thank you very much!

Let $F_1(\mathbf{x}, \mathbf{y}), \ldots, F_r(\mathbf{x}, \mathbf{y})$ be bihomogeneous polynomials with rational coefficients with bidegree $(d_1, d_2)$, which means $$ F_i( s x_1, \ldots, s x_{n_1} ; t y_1, \ldots, t y_{n_2} ) = s^{d_1} t^{d_2} F_i(\mathbf{x} ; \mathbf{y} ). $$ Let $V$ be the algebraic set defined by $F_1, \ldots, F_r$ in $\mathbb{C}^{n_1+ n_2}$, and let us denote $V_1, \ldots, V_T$ to be the irreducible components of $V$. Then I am guessing that the following is true, but I wasn't really sure how to prove or where to find a reference for: Let $1 \leq i \leq T$.

1. Suppose the point $(u_1, \ldots, u_{n_1}, v_{1}, \ldots, v_{n_2}) \in \mathbb{C}^{n_1+n_2}$ is contained in $V_i$. Then for any $s,t \in \mathbb{C}$ the point $(su_1, \ldots, su_{n_1}, tv_{1}, \ldots, tv_{n_2})$ is also contained in $V_i$.

2. $V_i$ contains points all points of the form $(0,\ldots, 0, t, \ldots, t)$ where there are $n_1$ $0$'s and $n_2$ $t$'s.

I would appreciate any comments or references. Thank you very much!