diff --git a/Сивочуб Алексей/README.md b/Сивочуб Алексей/README.md
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+# Теорема о квадрате
+## Ссылка на видеоразбор
+https://youtu.be/0Yp5sgddlko
+## Код из сайта
+    START_INTERACTIVE;;
+    let coordinations =
+    ["perpendicular", (** Lines (1,2) and (3,4) are perpendicular **)
+    <<(1_x - 2_x) * (3_x - 4_x) + (1_y - 2_y) * (3_y - 4_y) = 0>>;
+    "lengths_eq", (** Lines (1,2) and (3,4) have the same length **)
+    <<(1_x - 2_x)^2 + (1_y - 2_y)^2 = (3_x - 4_x)^2 + (3_y - 4_y)^2>>;
+    "is_midpoint", (** Point 1 is the midpoint of line (2,3) **)
+    <<2 * 1_x = 2_x + 3_x /\ 2 * 1_y = 2_y + 3_y>>];;
+    #Square theorem
+
+    (grobner_decide ** originate)
+    <<is_midpoint(m,a,c) /\ perpendicular(a,c,m,b)
+    ==> lengths_eq(a,b,b,c)>>;;
+    END_INTERACTIVE;
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diff --git a/Сивочуб Алексей/square.rkt b/Сивочуб Алексей/square.rkt
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+#lang racket/base
+
+(define (square x) (* x x))
+
+(define (lengths_eq x1 y1 x2 y2 x3 y3 x4 y4)
+(if (equal? (+ (square(- x1 x2)) (square(- y1 y2))) 
+(+ (square(- x3 x4)) (square(- y3 y4)))) 
+(displayln "Lines (1,2) and (3,4) have the same length.") 
+(displayln "Lines (1,2) and (3,4) do not have the same length.")))
+
+(define (perpendicular x1 y1 x2 y2 x3 y3 x4 y4)
+(if (equal? (+ (* (- x1 x2) (- x3 x4)) (* (- y1 y2) (- y3 y4))) 0 ) 
+#t #f
+))
+
+(define (is_midpoint x1 y1 x2 y2 x3 y3)
+(if (and (equal? (* 2 x1) (+ x2 x3)) (equal? (* 2 y1) (+ y2 y3)))
+(displayln "Point 1 is the midpoint of line (2,3).")
+(displayln "Point 1 is not the midpoint of line (2,3).")
+))
+
+
+(define (grobner_decide_mid a_x a_y b_x b_y c_x c_y d_x d_y m_x m_y)
+(if (and (is_midpoint m_x m_y a_x a_y c_x c_y) 
+    (perpendicular a_x a_y c_x c_y m_x m_y b_x b_y))
+    (begin 
+  (lengths_eq a_x a_y b_x b_y b_x b_y c_x c_y) 
+  (displayln "This is a square.") 
+  )
+  (displayln "This is not a square.") 
+))
+
+
+
+(grobner_decide_mid 0 0 0 2 2 2 2 0 1 1)
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