calculi
calculi — noun
1. the plural form of calculus, referring to two or more branches of the mathematic
the plural form of calculus, referring to two or more branches of the mathematical study of change — typically differential calculus (finding rates of change) and integral calculus (finding total values).
Differential and integral calculi allowed Defne to calculate the thrust needed for her model-rocket project.
differential/integral calculi as paired subjects
Nora found that mastering both calculi helped her predict the orbit of the newly discovered comet.
Niran enrolled in vector and tensor calculi courses at ETH Zurich to prepare for relativity research.
Before studying the two calculi, Jin completed courses in algebra and trigonometry.
Jin used differential and integral calculi to model the supply-and-demand curves in his economics project.
- calculus
singular form; used for the subject as a whole rather than multiple branches
文法句型
calculi + of + [field]
adjective + calculi
用法筆記
This is the plural of calculus in its mathematical sense. In everyday English, calculus is uncountable ("I studied calculus"), but the plural calculi appears in academic writing when comparing two or more systems or branches.
常見錯誤
2. systems of computation or reasoning that use specially designed symbols and rule
systems of computation or reasoning that use specially designed symbols and rules, for example in formal logic, symbolic logic, or computer science.
Defne studied three formal calculi in her logic seminar — propositional, predicate, and temporal logic.
formal calculi: systems of symbolic reasoning
Andrés compared predicate and modal calculi to see which described inference rules in legal reasoning more clearly.
The lambda calculus and process calculi were the two systems Soraya studied for her PhD in programming languages.
Gita compared three modal calculi for her thesis — one for necessity, one for possibility, and one for obligation.
Eric developed new temporal calculi to help an AI plan delivery routes when traffic conditions change suddenly.
- formal systems
broader term; includes any rule-governed system, not only symbolic ones
- logical systems
more specific; refers specifically to systems of logic
文法句型
adjective + calculi
calculi of + [field]
用法筆記
Frequently paired with an adjective naming the logical domain (propositional, predicate, modal, lambda). In this sense calculi is always a count noun in the plural — the singular calculus refers to one such system.
3. hard lumps made of mineral salts that form inside hollow organs or body ducts —
hard lumps made of mineral salts that form inside hollow organs or body ducts — for example, kidney stones in the urinary tract or gallstones in the gallbladder.
The X-ray showed multiple renal calculi in Padma's left kidney that required surgery.
renal calculi: term for kidney stones
The ultrasound showed that Apinya had biliary calculi blocking bile flow from her liver, causing sharp pain in her side.
biliary calculi: gallstones in the bile duct
Dr. Imran removed three calculi from the ureter during the outpatient procedure.
A diet rich in salt and low in water can increase the risk of forming urinary calculi.
The ultrasound revealed small calculi in Caleb's gallbladder that required regular monitoring.
- stones
everyday word; less technical than calculi (e.g., kidney stones)
- concretions
broader medical term; includes any hardened mass, not only mineral salts
文法句型
adjective + calculi
calculi in + [body part]
plural verb
用法筆記
This is the most common context for the word calculi in medical writing. The singular form calculus ("a kidney calculus") is also used but less frequent than the plural. Common anatomical adjectives: renal (kidney), biliary (gallbladder), urinary (bladder/ureter), pancreatic (pancreas), salivary (salivary gland).
常見錯誤
4. hard, crusty deposits of mineral salts that accumulate on the surfaces of teeth,
hard, crusty deposits of mineral salts that accumulate on the surfaces of teeth, especially near the gum line, also known as tartar.
The dental hygienist scraped away the calculi that had built up on Benjamin's molars.
dental calculi on teeth: professional cleaning
Regular flossing helps prevent the formation of dental calculi near the gum line.
Salma's dentist said her calculi were minimal because she brushed thoroughly after every meal.
Calculi on the lower front teeth are common because the salivary glands release minerals there.
The checkup showed no new calculi, so Nicholas only needed a standard cleaning.
- tartar
common everyday term; the preferred word outside medical contexts
文法句型
dental calculi
calculi on + [teeth/gums]
用法筆記
In dentistry, the uncountable noun tartar is far more common in everyday language. Calculi is the clinical term and appears mainly in dental records, textbooks, and research papers. The singular calculus ("a deposit of dental calculus") is used when referring to the material as one mass.
常見錯誤
5. a complex framework of connected parts or principles that function together as a
a complex framework of connected parts or principles that function together as an organized whole — often used metaphorically to describe moral, social, or political systems.
The moral calculi of different cultures can lead to very different ideas about justice and fairness.
metaphorical use: moral calculi
The intricate calculi of international trade law require years of specialised study.
Each society develops its own social calculi for weighing individual rights against the common good.
The political calculi of diplomacy shift with every change in government leadership.
In rural Vietnamese villages, emotional calculi — not written contracts — decide how land is divided among adult children.
- frameworks
broader; any structured set of ideas, not necessarily intricate
- systems
more general; less metaphorical than calculi
- machinery
metaphorical like calculi; suggests the moving parts of a system in operation
文法句型
the + adjective + calculi + of + [domain]
possessive + calculi
用法筆記
This sense is always metaphorical and highly formal. It typically appears with a domain adjective (moral, social, political, emotional) that names the type of system. The singular calculus is also used in the same metaphorical way (e.g., "the moral calculus of war").