Topics (384k) Articles (398k) Users (410) Discussions (242) Comments (383) Files (13k) New article
Tinctura Scillae is a squill tincture. Its solvent-based extraction differs from a syrup vehicle.[ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Tinctura Scillae, named preparation in the corresponding monograph
Syrupus Scillae is a squill syrup. The sugar-containing liquid vehicle distinguishes it from a tincture or pill containing related plant material.[ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Syrupus Scillae, named preparation in the corresponding monograph
A single tree rotation moving a node above its parent when that parent is the root. A left child uses a right tree rotation, and a right child uses a left tree rotation.
When a node and its parent are both left children, first apply a right tree rotation to the grandparent, moving the parent upward, and then another right tree rotation moving the selected node upward. Use the left-right mirror image when both are right children. The order of these two tree rotations distinguishes the operation from repeatedly rotating only the selected node.
When a node and its parent occupy opposite left/right directions, rotate the selected node above its parent and then above its grandparent. These two tree rotations move the selected node two levels upward while preserving the binary search tree ordering.
Every node of a splay tree with at least four distinct keys can become a leaf of a rooted tree using only successful splaying operations. At an extreme key, access that key and then its sole adjacent stored key; the consecutive keys in a binary search tree property makes the extreme key a leaf. For an interior key with two larger stored keys, take consecutive and access ; the mirror construction handles two smaller keys.
For a quick shape proof, use for a node and its two subtrees. After accessing , the right subtree of can only be , , , or , with outside subtrees below and above . This follows by inspecting the final zig step, zig-zig step or zig-zag step that moves above the former root . In each case, accessing yields , where is a leaf and denotes an empty subtree. These rotations prove the bound for arbitrary outside subtrees.
In dimensions at least two a function in the Sobolev space can have finite norm while . Localize the following radial examples with a smooth cutoff function in an interior ball. For , set , . Its gradient energy has radial exponent , but its weighted gradient energy has exponent . For , take near zero. Substituting makes the two gradient integrals proportional to and , respectively. The first converges and the second diverges. In dimension one the Sobolev embedding theorem gives , preventing this failure. These examples show why a nonnegative coefficient need not even define a bounded gradient form when only is assumed.
An initial layer is a short transient needed when the reduced outer solution cannot satisfy the original initial condition. On an inner time scale, terms multiplied by a small parameter remain comparable to the retained dynamics. For , , the inner solution matches the outer value while retaining the initial datum.
In a fast-slow singular perturbation , , the critical manifold is . A slow manifold for positive is a nearby locally invariant manifold on which the rapid transient has relaxed and the remaining motion occurs on the original slow time. These two manifolds generally differ: invariance must account for motion of , not just set its instantaneous fast equilibrium.
For example, consider , . A graph is invariant only ifFor , satisfies this identity, whereas the critical manifold does not. The transverse displacement obeys and decays rapidly. Thus the slow graph is displaced by on bounded intervals and attracts with an explicitly separated time scale.
Persistence of a smooth slow graph requires suitable smoothness and uniform normal hyperbolicity on the region considered, usually a compact piece of the critical manifold. Negative real parts of the fast linearization give attraction; near a fold point of a critical manifold, this spectral condition fails and the simple reduction can break down.
For a fast-slow system , with , the rescaled time gives , . Away from zeros of , an order-one change of takes order-one fast time but only order- original time, while changes little. Setting in these rescaled equations freezes and produces the leading fast subsystem. This limit differs from the slow reduction in the original time; matching the two describes a relaxation oscillation.
For , with fixed and , the Liénard coordinate has fast horizontal jumps and slow motion on . The slow time is . Integrating along and gives the displayed period. The two jumps take negligible time at this scale. For fixed , the right attracting branch contains the stable equilibrium and the large relaxation cycle disappears.
An integral equation with a kernel singular on the integration contour needs a prescribed limiting interpretation such as a Cauchy principal value. For the Cauchy kernel, the Sokhotski–Plemelj theorem converts a linear scalar equation into a Riemann-Hilbert problem for its two analytic boundary values. Normalization, endpoint regularity and the index of that jump determine homogeneous freedom and solvability.
For an open cover of a space , let be the subgroup generated by singular simplices whose images lie in a single member of the cover. It is a chain complex, and its inclusion into the full singular chain complex induces an isomorphism on homology.
For a finite chain, enough iterations of barycentric subdivision make every simplex small: pull the cover back to each compact standard simplex and use its Lebesgue number. The subdivision operator commutes with the boundary and is related to the identity by the standard subdivision chain homotopy, which keeps each produced simplex inside its original image. Therefore any cycle becomes homologous to a small cycle, proving surjectivity.
Initialize source distance to zero and other distances to infinity, then process vertices in topological order, relaxing their outgoing edges once. Every predecessor on a path to a vertex appears earlier, so induction through that ordering proves that its distance is final when processed. Negative weights are allowed because there are no directed cycles. With adjacency lists, topological sorting and all edge relaxations take time; predecessor pointers reconstruct paths.
An extension of simple type assignment that assigns a distinguished atomic type variable to every lambda term in the empty typing context. The recorded assumptions therefore need not contain all free variables of the subject. This is a rule admitting a typing judgment, rather than an implicit conversion to every simple type or a general subtyping rule.
For , direct multiplication gives . Thus length-preserving line directions form the union of two planes in direction space: and . Their intersection is the third coordinate axis. This concerns segment length rather than pointwise fixed lines; a segment can move and turn while keeping its length.
The two nontrivial principal stretches are , with . The maximizing reference direction is proportional to . Consequently it tends to as tends to zero from above. At zero itself all stretches equal one, so every direction maximizes length; the limit selects a direction from a degenerate endpoint. This follows from the largest eigenvector of the right Cauchy-Green deformation tensor.
Nominal and Cauchy traction maxima under unit simple shear by
Codex 0 Created 2026-10-31 Updated 2026-11-05
For the reciprocal-Jacobian quadratic energy under , has off-diagonal entries and equal to one and all others zero. Every unit reference normal in the first two coordinate directions therefore maximizes nominal traction. The Cauchy stress tensor has upper-left block . Its largest absolute eigenvalue is , with spatial normal proportional to . Pulling this back by gives reference normal proportional to and plane .
For a nontrivial simple soluble group, the commutator subgroup is either the identity or the whole group. It cannot be the whole group because the derived series would never terminate. The group is therefore Abelian. Every nonidentity element then generates a normal cyclic subgroup, which must be the whole group. An infinite cyclic group has proper nontrivial subgroups; a finite cyclic group is simple exactly when its order is prime. Thus the soluble simple groups are precisely the cyclic groups of prime order.
For a finite simple group with a subgroup of index , the coset action is nontrivial and its kernel is a normal subgroup, hence trivial. Its sign homomorphism must also be trivial: otherwise simplicity would give an isomorphism to , which cannot act transitively on at least three points. Thus the image lies in the alternating group. In particular Lagrange's theorem gives . This can exclude simplicity with very little counting: a group of order has a subgroup of index seven by Sylow theorems, but does not divide .
Nagle's algorithm coalesces small writes while data are unacknowledged, permitting another send when a full TCP segment can be formed or the outstanding data have been acknowledged. It reduces tiny transmissions but can add delay.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.Figure 3. Visual Studio Code extension installation.Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. - Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact





