Rules that someone made up -- Is that MATH?

      As frequent readers of this blog know, I am indebted to many people for their contributions of poems -- their own and links to others.  An alert to today's poem came from Canadian poet Alice Major -- with previous contibutions to this blog found at this link.   The poem, "BOUNDARY CONDITIONS"  by Sneha Madhavan-Reese was published in the journal Rattle.   I offer, below, its opening and closing stanzas, followed by a link to the complete poem.

from   BOUNDARY CONDITIONS     by   Sneha Madhavan-Reese

                    who but men blame the angels for the wild
                           exceptionalism of men?    —Sam Sax, “Anti-Zionist Abecedarian”

       Along the border of any governed region, there exists a value which must
       satisfy its laws. This is a rule I learned for solving differential equations.

Focus on FOUR

     Numerous poems by Canadian poet Alice Major connect to science and mathematics, and Major has connected me with Ottawa poet and mechanical engineer Sneha Madhavan-Reese -- who has shared with me not only poetry but also the new-to-me fact that her home city of  Ottawa lies on the traditional and unceded territory of the Algonquin Nation.  Here is Madhavan-Reese's poem, "Four," a thoughtful reminder of the vast versatility of mathematical notions.
   

       Four     by Sneha Madhavan-Reese

               Is 4 the same 4 for everybody? -- Pablo Neruda, The Book of Questions

       My mother draws her four with a right angle;

       my father's is pointed on top.  My daughter's four,

       half the time, is backwards.  Her sister signs,

       tucking a thumb into her raised palm.