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equations [2010/08/18 12:34] jipsen |
equations [2017/10/02 10:57] (current) jipsen |
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Here we list equations, with the shorter term on the right (if possible). | Here we list equations, with the shorter term on the right (if possible). | ||
- | |trivial equations: | $x = y$ $\quad f(x) = y$ $\quad x*y = z$ | $\Rightarrow$ one-element algebras || | + | |1 |trivial equations: | $x = y$ $\quad f(x) = y$ $\quad x*y = z$ | $\Rightarrow$ one-element algebras || |
- | |identity operation: | $f(x) = x$ ||| | + | |2 |identity operation: | $f(x) = x$ ||| |
- | |self-inverse operation: | $f(f(x)) = x$ ||| | + | |3 |involutive operation: | $f(f(x)) = x$ ||| |
- | |inverse operations: | $f(g(x)) = x$ ||| | + | |4 |inverse operations: | $f(g(x)) = x$ ||| |
- | |order-$n$ operation: | $f^n(x) = x$ ||| | + | |5 |inside absorption: | $f(g(x)) = f(x)$ ||| |
- | |$f$-idempotent | $f(f(x)) = f(x)$ ||| | + | |6 |outside absorption: | $f(g(x)) = g(x)$ ||| |
- | |constant operations: | $f(x) = 1$ $\quad f(x) = f(y)$ $\quad x*y = 1$ | $x*y = f(z)$ | $x*y = z*w$ | | + | |7 |order-$n$ operation: | $f^n(x) = x$ ||| |
- | |left projection: | $x*y = x$ | right projection: | $x*y = y$ | | + | |8 |$f$-idempotent | $f(f(x)) = f(x)$ ||| |
- | |idempotent: | $x*x = x$ ||| | + | |9 |constant operations: | $f(x) = 1$ $\quad f(x) = f(y)$ $\quad x*y = 1$ | $x*y = f(z)$ | $x*y = z*w$ | |
- | |$n$-potent: | $x^{n+1} = x^n$ ||| | + | |10 |left projection: | $x*y = x$ | right projection: | $x*y = y$ | |
- | |left identity: | $1*x = x$ | right identity: | $x*1 = x$ | | + | |11 |idempotent: | $x*x = x$ ||| |
- | |left zero: | $0*x = 0$ | right zero: | $x*0 = 0$ | | + | |12 |$n$-potent: | $x^{n+1} = x^n$ ||| |
- | |left $f$-projection: | $x*y = f(x)$ | right $f$-projection: | $x*y = f(y)$ | | + | |13 |left identity: | $1*x = x$ | right identity: | $x*1 = x$ | |
- | |square constant: | $x*x = 1$ ||| | + | |14 |left zero: | $0*x = 0$ | right zero: | $x*0 = 0$ | |
- | |square definition: | $x*x = f(x)$ ||| | + | |15 |left $f$-projection: | $x*y = f(x)$ | right $f$-projection: | $x*y = f(y)$ | |
- | |left constant multiple: | $1*x = f(x)$ | right constant multiple: | $x*1 = f(x)$ | | + | |16 |square constant: | $x*x = 1$ ||| |
- | |commutative: | $x*y = y*x$ ||| | + | |17 |square definition: | $x*x = f(x)$ ||| |
- | |left inverse: | $f(x)*x = 1$ | right inverse: | $x*f(x) = 1$ | | + | |18 |left constant multiple: | $1*x = f(x)$ | right constant multiple: | $x*1 = f(x)$ | |
- | |left $f$-identity: | $f(x)*x = x$ | right $f$-identity: | $x*f(x) = x$ | | + | |19 |commutative: | $x*y = y*x$ ||| |
- | |interassociative: | $x*(y+z) = (x+y)*z$ ||| | + | |20 |left inverse: | $f(x)*x = 1$ | right inverse: | $x*f(x) = 1$ | |
- | |associative: | $x*(y*z) = (x*y)*z$ ||| | + | |21 |left $f$-identity: | $f(x)*x = x$ | right $f$-identity: | $x*f(x) = x$ | |
- | |left commutativity: | $x*(y*z) = y*(x*z)$ | right commutativity: | $(x*y)*z = (x*z)*y$ | | + | |22 |interassociative: | $x*(y+z) = (x+y)*z$ ||| |
- | |left idempotent: | $x*(x*y) = x*y$ | right idempotent: | $(x*y)*y = x*y$ | | + | |23 |associative: | $x*(y*z) = (x*y)*z$ ||| |
- | |left rectangular: | $(x*y)*x = x$ | right rectangular: | $x*(y*x) = x$ | | + | |24 |left commutativity: | $x*(y*z) = y*(x*z)$ | right commutativity: | $(x*y)*z = (x*z)*y$ | |
- | |left distributive: | $x*(y+z) = (x*y)+(x*z)$ | right distributive: | $(x+y)*z = (x*z)+(y*z)$ | | + | |25 |left idempotent: | $x*(x*y) = x*y$ | right idempotent: | $(x*y)*y = x*y$ | |
- | |$f$-commutative: | $f(x)*f(y) = f(y)*f(x)$ ||| | + | |26 |left rectangular: | $(x*y)*x = x$ | right rectangular: | $x*(y*x) = x$ | |
- | |$f$-involutive: | $f(x*y) = f(y)*f(x)$ ||| | + | |27 |left absorption: | $(x*y)+x = x$ | right absorption: | $x+(y*x) = x$ | |
- | |$f$-interdistributive: | $f(x*y) = f(x)+f(y)$ ||| | + | |28 |left absorption1: | $(x*y)+y = y$ | right absorption1: | $y+(x*y) = y$ | |
- | |$f$-distributive: | $f(x*y) = f(x)*f(y)$ | also $f$-linear || | + | |29 |left subtraction: | $x*(x+y) = y$ | right subtraction: | $(y+x)*x = y$ | |
- | |left $f$-constant multiple: | $f(1*x) = 1*f(x)$ | right $f$-constant multiple: | $f(x*1) = f(x)*1$ | | + | |30 |left distributive: | $x*(y+z) = (x*y)+(x*z)$ | right distributive: | $(x+y)*z = (x*z)+(y*z)$ | |
- | |left twisted: | $f(x*y)*x = x*f(y)$ | right twisted: | $x*f(y*x) = f(y)*x$ | | + | |31 |left self-distributive: | $x*(y*z) = (x*y)*(x*z)$ | right distributive: | $(x*y)*z = (x*z)*(y*z)$ | |
- | |left locality: | $f(f(x)*y) = f(x*y)$ | right locality: | $f(x*f(y)) = f(x*y)$ | | + | |32 |$f$-commutative: | $f(x)*f(y) = f(y)*f(x)$ ||| |
- | |left $f$-distributive: | $f(f(x)*y) = f(x)*f(y)$ | right $f$-distributive: | $f(x*f(y)) = f(x)*f(y)$ | | + | |33 |$f$-involutive: | $f(x*y) = f(y)*f(x)$ ||| |
- | |left $f$-absorbtive: | $f(x)*f(x*y) = f(x*y)$ | right $f$-absorbtive: | $f(x*y)*f(y)) = f(x*y)$ | | + | |34 |$f$-interdistributive: | $f(x*y) = f(x)+f(y)$ ||| |
- | |entropic: | $(x*y)*(z*w) = (x*z)*(y*w)$ ||| | + | |35 |$f$-distributive: | $f(x*y) = f(x)*f(y)$ | also $f$-linear || |
- | |paramedial: | $(x*y)*(z*w) = (w*y)*(z*x)$ ||| | + | |36 |left $f$-constant multiple: | $f(1*x) = 1*f(x)$ | right $f$-constant multiple: | $f(x*1) = f(x)*1$ | |
+ | |37 |left twisted: | $f(x*y)*x = x*f(y)$ | right twisted: | $x*f(y*x) = f(y)*x$ | | ||
+ | |38 |left locality: | $f(f(x)*y) = f(x*y)$ | right locality: | $f(x*f(y)) = f(x*y)$ | | ||
+ | |39 |left $f$-distributive: | $f(f(x)*y) = f(x)*f(y)$ | right $f$-distributive: | $f(x*f(y)) = f(x)*f(y)$ | | ||
+ | |40 |left $f$-absorbtive: | $f(x)*f(x*y) = f(x*y)$ | right $f$-absorbtive: | $f(x*y)*f(y)) = f(x*y)$ | | ||
+ | |41 |flexible: | $(x*y)*x = x*(y*x)$ ||| | ||
+ | |42 |entropic: | $(x*y)*(z*w) = (x*z)*(y*w)$ ||| | ||
+ | |43 |paramedial: | $(x*y)*(z*w) = (w*y)*(z*x)$ ||| | ||
+ | |44 |Moufang1: | $((x*y)*x)*z = x*(y*(x*z))$ | Moufang2: | $((x*y)*z)*y = x*(y*(z*y))$ | | ||
+ | |45 |Moufang3: | $(x*y)*(z*x) = (x*(y*z))*x$ | Moufang4: | $(x*y)*(z*x) = x*((y*z)*x)$ | | ||
+ | Here are the identities in the syntax of the Lean Theorem Prover | ||
+ | |||
+ | <code> | ||
+ | section identities | ||
+ | |||
+ | variables {α: Type u} {β: Type v} | ||
+ | variables f g: α → α → α | ||
+ | variables h k: α → α | ||
+ | variable c: α | ||
+ | local notation a⬝b := f a b | ||
+ | local notation a+b := g a b | ||
+ | local notation a⁻¹ := h a | ||
+ | local notation 1 := c | ||
+ | local notation 0 := c | ||
+ | |||
+ | def involutive := ∀x, h(h x) = x | ||
+ | def inverse_operations := ∀x, h(k x) = x | ||
+ | def left_absorption := ∀x, h(k x) = k x | ||
+ | def right_absorption := ∀x, h(k x) = h x | ||
+ | def unary_idempotent := ∀x, h(h x) = h x | ||
+ | def idempotent := ∀x, x⬝x = x | ||
+ | def left_identity := ∀x, 1⬝x = x | ||
+ | def right_identity := ∀x, x⬝1 = x | ||
+ | def left_zero := ∀x, 0⬝x = 0 | ||
+ | def right_zero := ∀x, x⬝0 = 0 | ||
+ | def left_inverse := ∀x, x⁻¹⬝x = 1 | ||
+ | def right_inverse := ∀x, x⬝x⁻¹ = 1 | ||
+ | def left_const_mult := ∀x, c⬝x = h x | ||
+ | def right_const_mult := ∀x, x⬝c = h x | ||
+ | def square_constant := ∀x, x⬝x = c | ||
+ | def square_unary := ∀x, x⬝x = h x | ||
+ | def left_unary_identity := ∀x, (h x)⬝x = x | ||
+ | def right_unary_identity := ∀x, x⬝(h x) = x | ||
+ | def left_unary_const_mult := ∀x, h(c⬝x) = c⬝(h x) | ||
+ | def right_unary_const_mult := ∀x, h(x⬝c) = (h x)⬝c | ||
+ | def commutative := ∀x y, x⬝y = y⬝x | ||
+ | def left_unary_projection := ∀x y, x⬝y = h x | ||
+ | def right_unary_projection := ∀x y, x⬝y = h y | ||
+ | def left_idempotent := ∀x y, x⬝(x⬝y) = x⬝y | ||
+ | def right_idempotent := ∀x y, (x⬝y)⬝y = x⬝y | ||
+ | def left_rectangular := ∀x y, (x⬝y)⬝x = x | ||
+ | def right_rectangular := ∀x y, x⬝(y⬝x) = x | ||
+ | def left_absorption1 := ∀x y, (x⬝y)+y = y | ||
+ | def right_absorption1 := ∀x y, y+(x⬝y) = y | ||
+ | def left_absorption2 := ∀x y, (x⬝y)+x = x | ||
+ | def right_absorption2 := ∀x y, x+(y⬝x) = x | ||
+ | def left_subtraction := ∀x y, x⬝(x+y) = y | ||
+ | def right_subtraction := ∀x y, (y+x)⬝x = y | ||
+ | def unary_commutative := ∀x y, (h x)⬝(h y) = (h y)⬝(h x) | ||
+ | def unary_involutive := ∀x y, h(x⬝y) = (h y)⬝(h x) | ||
+ | def interdistributive := ∀x y, h(x⬝y) = (h x)+(h y) | ||
+ | def unary_distributive := ∀x y, h(x⬝y) = (h x)⬝(h y) | ||
+ | def left_twisted := ∀x y, (h(x⬝y))⬝x = x⬝(h y) | ||
+ | def right_twisted := ∀x y, x⬝(h(y⬝x)) = (h y)⬝x | ||
+ | def left_locality := ∀x y, h((h x)⬝y) = h(x⬝y) | ||
+ | def right_locality := ∀x y, h(x⬝(h y)) = h(x⬝y) | ||
+ | def left_unary_distributive := ∀x y, h((h x)⬝y) = (h x)⬝(h y) | ||
+ | def right_unary_distributive:= ∀x y, h(x⬝(h y)) = (h x)⬝(h y) | ||
+ | def left_absorbtive := ∀x y, (h x)⬝(h(x⬝y)) = h(x⬝y) | ||
+ | def right_absorbtive := ∀x y, (h(x⬝y))⬝(h y) = h(x⬝y) | ||
+ | def flexible := ∀x y, (x⬝y)⬝x = x⬝(y⬝x) | ||
+ | def associative := ∀x y z, x⬝(y⬝z) = (x⬝y)⬝z | ||
+ | def left_commutative := ∀x y z, x⬝(y⬝z) = y⬝(x⬝z) | ||
+ | def right_commutative := ∀x y z, (x⬝y)⬝z = (x⬝z)⬝y | ||
+ | def interassociative1 := ∀x y z, x⬝(y+z) = (x⬝y)+z | ||
+ | def interassociative2 := ∀x y z, x⬝(y+z) = (x+y)⬝z | ||
+ | def left_distributive := ∀x y z, x⬝(y+z) = (x⬝y)+(x⬝z) | ||
+ | def right_distributive := ∀x y z, (x+y)⬝z = (x⬝z)+(y⬝z) | ||
+ | def left_self_distributive := ∀x y z, x⬝(y⬝z) = (x⬝y)⬝(x⬝z) | ||
+ | def right_self_distributive := ∀x y z, (x⬝y)⬝z = (x⬝z)⬝(y⬝z) | ||
+ | def Moufang1 := ∀x y z, ((x⬝y)⬝x)⬝z = x⬝(y⬝(x⬝z)) | ||
+ | def Moufang2 := ∀x y z, ((x⬝y)⬝z)⬝y = x⬝(y⬝(z⬝y)) | ||
+ | def Moufang3 := ∀x y z, (x⬝y)⬝(z⬝x) = (x⬝(y⬝z))⬝x | ||
+ | def Moufang4 := ∀x y z, (x⬝y)⬝(z⬝x) = x⬝((y⬝z)⬝x) | ||
+ | def entropic := ∀x y z w, (x⬝y)⬝(z⬝w) = (x⬝z)⬝(y⬝w) | ||
+ | def paramedial := ∀x y z w, (x⬝y)⬝(z⬝w) = (w⬝y)⬝(z⬝x) | ||
+ | |||
+ | |||
+ | end identities | ||
+ | </code> |
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