This is an archive of a list of "missing" topics in mathematics. Notability should be established independently before articles are created.

See also: User:Mathbot/Changes to mathlists.

• Bluelinks: 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z (entries removed from the above lists because they exist on Wikipedia)
• Sources for the lists: MathWorld, Springer Encyclopaedia of Mathematics, Charles Matthews' maths lists, St Andrew's, PlanetMath.

1. NRoots possibly Nroots ( wikisearch; web; books)
2. NSW Number possibly Nsw number or NSW number ( wikisearch; web; books)
3. Nu Function possibly Nu function ( wikisearch; web; books)
4. Nuclear bilinear form ( wikisearch; web; books)
5. Nuclear norm ( wikisearch; web; books)
6. Nucleolus of a game ( wikisearch; web; books)
7. Nugatory Crossing possibly Nugatory crossing ( wikisearch; web; books)
8. Null object of a category ( wikisearch; web; books)
9. Null Tetrad possibly Null tetrad ( wikisearch; web; books)
10. Nullhomotopic map ( wikisearch; web; books)
11. Number Field Order possibly Number field order ( wikisearch; web; books)
12. Number Field Signature possibly Number field signature ( wikisearch; web; books)
13. Number Group possibly Number group ( wikisearch; web; books)
14. Number Guessing possibly Number guessing ( wikisearch; web; books)

1. Number Length possibly Number length ( wikisearch; web; books)
2. Number of ultrafilters ( wikisearch; web; books)
3. Number Pattern possibly Number pattern ( wikisearch; web; books)
4. Number Picking possibly Number picking ( wikisearch; web; books)
5. Number Pyramid possibly Number pyramid ( wikisearch; web; books)
6. Number Shape possibly Number shape ( wikisearch; web; books)
7. Number Theoretic Character possibly Number theoretic character ( wikisearch; web; books)
8. Number Theoretic Function possibly Number theoretic function ( wikisearch; web; books)
9. Number theory, probabilistic methods in possibly Probabilistic methods in number theory or Probabilistic methods in Number theory ( wikisearch; web; books)
10. Number Wall possibly Number wall ( wikisearch; web; books)
11. Numbers, representations of possibly Representations of numbers or Representations of Numbers ( wikisearch; web; books)
12. Numerable set ( wikisearch; web; books)
13. Nuttall Q-Function possibly Nuttall q-function or Nuttall Q-function ( wikisearch; web; books)

1. O-direct union ( wikisearch; web; books)
2. O-distribution ( wikisearch; web; books)
3. O-group ( wikisearch; web; books)
4. Oberbeck-Boussinesq equations possibly Oberbeck-boussinesq equations ( wikisearch; web; books)
5. Object in a category ( wikisearch; web; books)
6. Object, geometric possibly Geometric object or Geometric Object ( wikisearch; web; books)
7. Oblate Spheroid Geodesic possibly Oblate spheroid geodesic ( wikisearch; web; books)
8. Oblate Spheroidal Wave Function possibly Oblate spheroidal wave function ( wikisearch; web; books)
9. Oblique Coordinate System possibly Oblique coordinate system ( wikisearch; web; books)
10. Oblique Coordinates possibly Oblique coordinates ( wikisearch; web; books)
11. Oblique Cylinder possibly Oblique cylinder ( wikisearch; web; books)
12. Oblique derivative ( wikisearch; web; books)
13. Oblique Prism possibly Oblique prism ( wikisearch; web; books)
14. Oblique Triangle possibly Oblique triangle ( wikisearch; web; books)

1. Obstacle scattering ( wikisearch; web; books)
2. Oceanology, mathematical problems in possibly Mathematical problems in oceanology or Mathematical problems in Oceanology ( wikisearch; web; books)
3. Ochoa Curve possibly Ochoa curve ( wikisearch; web; books)
4. Ockham Algebra possibly Ockham algebra ( wikisearch; web; books)
5. Octacode ( wikisearch; web; books)
6. Octagonal Heptagonal Number possibly Octagonal heptagonal number ( wikisearch; web; books)
7. Octagonal Hexagonal Number possibly Octagonal hexagonal number ( wikisearch; web; books)
8. Octagonal Pentagonal Number possibly Octagonal pentagonal number ( wikisearch; web; books)
9. Octagonal Square Number possibly Octagonal square number ( wikisearch; web; books)
10. Octagonal Triangular Number possibly Octagonal triangular number ( wikisearch; web; books)
11. Octahedral Equation possibly Octahedral equation ( wikisearch; web; books)
12. Octahedral space ( wikisearch; web; books)
13. Octahedron 10-Compound possibly Octahedron 10-compound ( wikisearch; web; books)
14. Octahedron 2-Compound possibly Octahedron 2-compound ( wikisearch; web; books)

1. Octahedron 3-Compound possibly Octahedron 3-compound ( wikisearch; web; books)
2. Octahedron 4-Compound possibly Octahedron 4-compound ( wikisearch; web; books)
3. Octahedron 5-Compound possibly Octahedron 5-compound ( wikisearch; web; books)
4. Octahedron 6-Compound possibly Octahedron 6-compound ( wikisearch; web; books)
5. Octahedron Stellation possibly Octahedron stellation ( wikisearch; web; books)
6. Octahedron Tetrahedron Picking possibly Octahedron tetrahedron picking ( wikisearch; web; books)
7. Octatetracontagon ( wikisearch; web; books)
8. Octiamond Tiling possibly Octiamond tiling ( wikisearch; web; books)
9. Octic Reciprocity Theorem possibly Octic reciprocity theorem ( wikisearch; web; books)
10. Octic Surface possibly Octic surface ( wikisearch; web; books)
11. Odd Divisor Function possibly Odd divisor function ( wikisearch; web; books)
12. Odd Graph possibly Odd graph ( wikisearch; web; books)

1. Odd Part possibly Odd part ( wikisearch; web; books)
2. Odd Power possibly Odd power ( wikisearch; web; books)
3. Odd Sequence possibly Odd sequence ( wikisearch; web; books)
4. Odd Triple possibly Odd triple ( wikisearch; web; books)
5. Odlyzko bounds ( wikisearch; web; books)
6. Oesterlé-Masser Conjecture possibly Oesterlé-Masser conjecture or Oesterlé-masser conjecture ( wikisearch; web; books)
7. Of Order possibly Of order ( wikisearch; web; books)
8. Of Shape possibly Of shape ( wikisearch; web; books)
9. Offset Curves possibly Offset curves ( wikisearch; web; books)
10. Offset Rings possibly Offset rings ( wikisearch; web; books)
11. Oka theorems ( wikisearch; web; books)

1. Oldknow Points possibly Oldknow points ( wikisearch; web; books)
2. Olevskii transform ( wikisearch; web; books)
3. Oligomorphic permutation group ( wikisearch; web; books)
4. Oliveira's Minimal Surface possibly Oliveira's minimal surface ( wikisearch; web; books)
5. Omega-completeness ( wikisearch; web; books)
6. Omega-squared distribution ( wikisearch; web; books)
7. Omega2 Constant possibly Omega2 constant ( wikisearch; web; books)
8. Omnific Integer possibly Omnific integer ( wikisearch; web; books)
9. One hundred sixty-three ( wikisearch; web; books)
10. One-dimensional manifold ( wikisearch; web; books)
11. One-factor ( wikisearch; web; books)
12. One-line notation for permutations ( wikisearch; web; books)
13. One-Max Property possibly One-max property or One-Max property ( wikisearch; web; books)
14. One-Mouth Theorem possibly One-mouth theorem ( wikisearch; web; books)
15. One-Ninth Constant possibly One-ninth constant ( wikisearch; web; books)

1. One-One Complete possibly One-one complete ( wikisearch; web; books)
2. One-parameter semi-group ( wikisearch; web; books)
3. One-parameter transformation group ( wikisearch; web; books)
4. One-Seventh Ellipse possibly One-seventh ellipse ( wikisearch; web; books)
5. One-sided and two-sided surfaces ( wikisearch; web; books)
6. One-sided normality of subsemigroup ( wikisearch; web; books)
7. One-Term Relation possibly One-term relation ( wikisearch; web; books)
8. One-to-one function from onto function ( wikisearch; web; books)
9. Only Critical Point in Town Test possibly Only critical point in town test ( wikisearch; web; books)
10. Onsager Differential Equation possibly Onsager differential equation ( wikisearch; web; books)
11. Open Manifold possibly Open manifold ( wikisearch; web; books)
12. Open Sentential Formula possibly Open sentential formula ( wikisearch; web; books)
13. Opening Angle possibly Opening angle ( wikisearch; web; books)
14. OpenPFGW possibly Openpfgw ( wikisearch; web; books)

1. Operational Mathematics possibly Operational mathematics ( wikisearch; web; books)
2. Operations on consequence operators ( wikisearch; web; books)
3. Operations on distributions ( wikisearch; web; books)
4. Operations on relations ( wikisearch; web; books)
5. Operator Calculus possibly Operator calculus ( wikisearch; web; books)
6. Operator colligation ( wikisearch; web; books)
7. Operator ergodic theorem ( wikisearch; web; books)
8. Operator group ( wikisearch; web; books)
9. Operator homomorphism ( wikisearch; web; books)
10. Operator monotone ( wikisearch; web; books)
11. Operator vessel ( wikisearch; web; books)
12. Operator-irreducible representation ( wikisearch; web; books)
13. Ophiuride ( wikisearch; web; books)

1. Opposite polynomial ( wikisearch; web; books)
2. Opposite Side possibly Opposite side ( wikisearch; web; books)
3. Opposition involution ( wikisearch; web; books)
4. Optical length ( wikisearch; web; books)
5. Optimal decoding ( wikisearch; web; books)
6. Optimal guarantee strategy ( wikisearch; web; books)
7. Optimal programming control ( wikisearch; web; books)
8. Optimal quadrature ( wikisearch; web; books)
9. Optimal singular regime ( wikisearch; web; books)
10. Optimal sliding regime ( wikisearch; web; books)
11. Optimal synthesis control ( wikisearch; web; books)
12. Optimal trajectory ( wikisearch; web; books)
13. Optimality principle ( wikisearch; web; books)
14. Optimality, sufficient conditions for possibly Sufficient conditions for optimality or Sufficient conditions for Optimality ( wikisearch; web; books)
15. Optimization of a computational method ( wikisearch; web; books)

1. Optimization of computational algorithms ( wikisearch; web; books)
2. Optional random process ( wikisearch; web; books)
3. Optional sigma-algebra ( wikisearch; web; books)
4. Orbifold Notation possibly Orbifold notation ( wikisearch; web; books)
5. Orbit stability ( wikisearch; web; books)
6. Orchard Problem possibly Orchard problem ( wikisearch; web; books)
7. Orchard Visibility Problem possibly Orchard visibility problem ( wikisearch; web; books)
8. Order (of a graph) ( wikisearch; web; books)
9. Order (of a ring) ( wikisearch; web; books)
10. Order (on a set) ( wikisearch; web; books)
11. Order in an algebra ( wikisearch; web; books)
12. Order of a compound asymptotic ( wikisearch; web; books)
13. Order of a profinite group ( wikisearch; web; books)

1. Order of an elliptic function ( wikisearch; web; books)
2. Order of contact ( wikisearch; web; books)
3. Order of elements in finite groups ( wikisearch; web; books)
4. Order of factors in infinite product ( wikisearch; web; books)
5. Order valuation ( wikisearch; web; books)
6. Orderable group ( wikisearch; web; books)
7. Ordered Factorization possibly Ordered factorization ( wikisearch; web; books)
8. Ordered groupoid ( wikisearch; web; books)
9. Ordered Pairs Representation possibly Ordered pairs representation ( wikisearch; web; books)
10. Ordered semi-group ( wikisearch; web; books)
11. Ordered space ( wikisearch; web; books)
12. Ordered sum ( wikisearch; web; books)
13. Ordered Tree possibly Ordered tree ( wikisearch; web; books)

1. Ordering Axioms possibly Ordering axioms ( wikisearch; web; books)
2. Orderless ( wikisearch; web; books)
3. Orders in a number field ( wikisearch; web; books)
4. Orders of elements in integral domain ( wikisearch; web; books)
5. Ordinal Comparison possibly Ordinal comparison ( wikisearch; web; books)
6. Ordinary Differential Equation Order possibly Ordinary differential equation order ( wikisearch; web; books)
7. Ordinary Differential Equation System with Constant Coefficients possibly Ordinary differential equation system with constant coefficients or Ordinary differential equation System with constant coefficients ( wikisearch; web; books)
8. Ordinary Double Point possibly Ordinary double point ( wikisearch; web; books)
9. Ordinary Line possibly Ordinary line ( wikisearch; web; books)
10. Ordinary Point possibly Ordinary point ( wikisearch; web; books)
11. Ordinary Surface possibly Ordinary surface ( wikisearch; web; books)
12. Ordinary Topology possibly Ordinary topology ( wikisearch; web; books)
13. Ore Algebra possibly Ore algebra ( wikisearch; web; books)
14. Ore Graph possibly Ore graph ( wikisearch; web; books)
15. Ore's Conjecture possibly Ore's conjecture ( wikisearch; web; books)

1. Orientable fibration ( wikisearch; web; books)
2. Orientation (complex analysis) ( wikisearch; web; books)
3. Orientation class ( wikisearch; web; books)
4. Oriented cobordism ( wikisearch; web; books)
5. Oriented cobordism ring ( wikisearch; web; books)
6. Oriented Knot possibly Oriented knot ( wikisearch; web; books)
7. Oriented Link possibly Oriented link ( wikisearch; web; books)
8. Oriented Tree possibly Oriented tree ( wikisearch; web; books)
9. Orientifold string theory ( wikisearch; web; books)
10. Original Triangle possibly Original triangle ( wikisearch; web; books)
11. Origins of Wedderburn's theorem possibly Origins of wedderburn's theorem ( wikisearch; web; books)
12. Orlicz class ( wikisearch; web; books)
13. Orlicz-Lorentz space possibly Orlicz-lorentz space ( wikisearch; web; books)
14. Ornstein-Chacon ergodic theorem possibly Ornstein-chacon ergodic theorem ( wikisearch; web; books)

1. Orr's Theorem possibly Orr's theorem ( wikisearch; web; books)
2. Orr-Sommerfeld Differential Equation possibly Orr-sommerfeld differential equation or Orr-Sommerfeld differential equation ( wikisearch; web; books)
3. Orthic Axis possibly Orthic axis ( wikisearch; web; books)
4. Orthic Inconic possibly Orthic inconic ( wikisearch; web; books)
5. Orthobicupola ( wikisearch; web; books)
6. Orthobirotunda ( wikisearch; web; books)
7. Orthocentric Centroid possibly Orthocentric centroid ( wikisearch; web; books)
8. Orthocentric Coordinates possibly Orthocentric coordinates ( wikisearch; web; books)
9. Orthocentric Line possibly Orthocentric line ( wikisearch; web; books)
10. Orthocentric Quadrangle possibly Orthocentric quadrangle ( wikisearch; web; books)
11. Orthocentric Quadrilateral possibly Orthocentric quadrilateral ( wikisearch; web; books)
12. Orthocentroidal Circle possibly Orthocentroidal circle ( wikisearch; web; books)
13. Orthocorrespondent ( wikisearch; web; books)
14. Orthocubic ( wikisearch; web; books)
15. Orthocupolarotunda ( wikisearch; web; books)

1. Orthodiagonal Quadrangle possibly Orthodiagonal quadrangle ( wikisearch; web; books)
2. Orthogonal Circles possibly Orthogonal circles ( wikisearch; web; books)
3. Orthogonal Coordinate System possibly Orthogonal coordinate system ( wikisearch; web; books)
4. Orthogonal Curves possibly Orthogonal curves ( wikisearch; web; books)
5. Orthogonal Decomposition possibly Orthogonal decomposition ( wikisearch; web; books)
6. Orthogonal direct sum ( wikisearch; web; books)
7. Orthogonal double-sweep method ( wikisearch; web; books)
8. Orthogonal factorization system in a category ( wikisearch; web; books)
9. Orthogonal Group Representations possibly Orthogonal group representations ( wikisearch; web; books)
10. Orthogonal Involution possibly Orthogonal involution ( wikisearch; web; books)
11. Orthogonal Lie Algebra possibly Orthogonal lie algebra or Orthogonal Lie algebra ( wikisearch; web; books)
12. Orthogonal Lines possibly Orthogonal lines ( wikisearch; web; books)
13. Orthogonal net ( wikisearch; web; books)
14. Orthogonal polynomials on a complex domain ( wikisearch; web; books)
15. Orthogonal Rotation Group possibly Orthogonal rotation group ( wikisearch; web; books)

1. Orthogonal series ( wikisearch; web; books)
2. Orthogonal Sum possibly Orthogonal sum ( wikisearch; web; books)
3. Orthogonal Surfaces possibly Orthogonal surfaces ( wikisearch; web; books)
4. Orthogonal Tensors possibly Orthogonal tensors ( wikisearch; web; books)
5. Orthogonality Condition possibly Orthogonality condition ( wikisearch; web; books)
6. Orthogonalization method ( wikisearch; web; books)
7. Orthogonalization of a system of functions ( wikisearch; web; books)
8. Orthoharmonic ( wikisearch; web; books)
9. Orthojoin ( wikisearch; web; books)
10. Orthologic Triangles possibly Orthologic triangles ( wikisearch; web; books)
11. Orthology Center possibly Orthology center ( wikisearch; web; books)
12. Orthomorphic Projection possibly Orthomorphic projection ( wikisearch; web; books)
13. Orthonormal Functions possibly Orthonormal functions ( wikisearch; web; books)
14. Orthonormal system ( wikisearch; web; books)

1. Orthopolar Line possibly Orthopolar line ( wikisearch; web; books)
2. Orthoptic Circle of the Steiner Inellipse possibly Orthoptic circle of the Steiner Inellipse or Orthoptic circle of the steiner inellipse ( wikisearch; web; books)
3. Orthoptic Curve possibly Orthoptic curve ( wikisearch; web; books)
4. Orthosymmetric Matrix possibly Orthosymmetric matrix ( wikisearch; web; books)
5. Orthotransversal ( wikisearch; web; books)
6. Oscillating Function possibly Oscillating function ( wikisearch; web; books)
7. Oscillating integral ( wikisearch; web; books)
8. Oscillating kernel ( wikisearch; web; books)
9. Oscillating matrix ( wikisearch; web; books)
10. Oscillating solution ( wikisearch; web; books)
11. Oscillation Land possibly Oscillation land ( wikisearch; web; books)
12. Oscillation of a function ( wikisearch; web; books)
13. Oscillations, theory of possibly Theory of oscillations or Theory of Oscillations ( wikisearch; web; books)
14. Oscillatory Function possibly Oscillatory function ( wikisearch; web; books)

1. Osculating Interpolation possibly Osculating interpolation ( wikisearch; web; books)
2. Osculating paraboloid ( wikisearch; web; books)
3. Osculating quadric ( wikisearch; web; books)
4. Osculating Sphere possibly Osculating sphere ( wikisearch; web; books)
5. Osedelec Theorem possibly Osedelec theorem ( wikisearch; web; books)
6. Osserman conjecture ( wikisearch; web; books)
7. Ostrogradski formula ( wikisearch; web; books)
8. Ostrogradski method ( wikisearch; web; books)
9. Ostrogradski-Liouville formula possibly Ostrogradski-liouville formula ( wikisearch; web; books)
10. Ostrowski's Inequality possibly Ostrowski's inequality ( wikisearch; web; books)
11. Ostrowski's valuation theorem ( wikisearch; web; books)
12. Otter's Theorem possibly Otter's theorem ( wikisearch; web; books)
13. Ouchi Illusion possibly Ouchi illusion ( wikisearch; web; books)

1. Oudor ( wikisearch; web; books)
2. Oui-Ja Board Curve possibly Oui-ja board curve or Oui-Ja board curve ( wikisearch; web; books)
3. Out-Shuffle possibly Out-shuffle ( wikisearch; web; books)
4. Outer Inscribed Squares Triangle possibly Outer inscribed squares triangle ( wikisearch; web; books)
5. Outer multiplication ( wikisearch; web; books)
6. Outer Napoleon Circle possibly Outer napoleon circle or Outer Napoleon circle ( wikisearch; web; books)
7. Outer Napoleon Point possibly Outer napoleon point or Outer Napoleon point ( wikisearch; web; books)
8. Outer Napoleon Triangle possibly Outer napoleon triangle or Outer Napoleon triangle ( wikisearch; web; books)
9. Outer Pentagon Point possibly Outer pentagon point ( wikisearch; web; books)
10. Outer Quermass possibly Outer quermass ( wikisearch; web; books)
11. Outer Soddy Center possibly Outer soddy center or Outer Soddy center ( wikisearch; web; books)
12. Outer Soddy Circle possibly Outer soddy circle or Outer Soddy circle ( wikisearch; web; books)
13. Outer Vecten Circle possibly Outer vecten circle or Outer Vecten circle ( wikisearch; web; books)
14. Outer Vecten Point possibly Outer vecten point or Outer Vecten point ( wikisearch; web; books)
15. Outer Vecten Triangle possibly Outer vecten triangle or Outer Vecten triangle ( wikisearch; web; books)

1. Output controllability ( wikisearch; web; books)
2. Oval of Descartes possibly Oval of descartes ( wikisearch; web; books)
3. Over-convergence ( wikisearch; web; books)
4. Overcomplete System possibly Overcomplete system ( wikisearch; web; books)
5. Overlapfree Word possibly Overlapfree word ( wikisearch; web; books)
6. Overlapping Rectangles possibly Overlapping rectangles ( wikisearch; web; books)
7. Overlapping Resonance Method possibly Overlapping resonance method ( wikisearch; web; books)
8. P test ( wikisearch; web; books)
9. (p,q) unshuffle ( wikisearch; web; books)
10. P-adic analytic ( wikisearch; web; books)
11. P-adic canonical form ( wikisearch; web; books)
12. P-adic cyclotomic character ( wikisearch; web; books)
13. P-adic exponential and p-adic logarithm ( wikisearch; web; books)

1. P-adic regulator ( wikisearch; web; books)
2. P-Circle possibly P-circle ( wikisearch; web; books)
3. P-Elementary Subgroup possibly P-elementary subgroup ( wikisearch; web; books)
4. P-extension ( wikisearch; web; books)
5. P-Good Path possibly P-good path ( wikisearch; web; books)
6. P-Layer possibly P-layer ( wikisearch; web; books)
7. P-part of a group element of finite order ( wikisearch; web; books)
8. P-point ( wikisearch; web; books)
9. P-Polynomial possibly P-polynomial ( wikisearch; web; books)
10. P-primary component ( wikisearch; web; books)
11. P-Problem possibly P-problem ( wikisearch; web; books)

1. P-rank ( wikisearch; web; books)
2. P-ring ( wikisearch; web; books)
3. P-Sasakian manifold possibly P-sasakian manifold ( wikisearch; web; books)
4. P-separable group ( wikisearch; web; books)
5. P-Signature possibly P-signature ( wikisearch; web; books)
6. P-solvable group ( wikisearch; web; books)
7. P-subgroup ( wikisearch; web; books)
8. P-Symbol possibly P-symbol ( wikisearch; web; books)
9. Padé Conjecture possibly Padé conjecture ( wikisearch; web; books)
10. Page theorem ( wikisearch; web; books)
11. Painlevé function ( wikisearch; web; books)
12. Painlevé problem ( wikisearch; web; books)
13. Painlevé test ( wikisearch; web; books)

1. Painlevé theorem ( wikisearch; web; books)
2. Painlevé-type equations ( wikisearch; web; books)
3. Pair Group possibly Pair group ( wikisearch; web; books)
4. Pair Groupoid possibly Pair groupoid ( wikisearch; web; books)
5. Pair Sum possibly Pair sum ( wikisearch; web; books)
6. Paired comparison model ( wikisearch; web; books)
7. Pairwise balanced design ( wikisearch; web; books)
8. Pairwise comaximal ideals property ( wikisearch; web; books)
9. Palais theorem ( wikisearch; web; books)
10. Paley Class possibly Paley class ( wikisearch; web; books)
11. Paley-Weiner space possibly Paley-weiner space ( wikisearch; web; books)
12. Palindromic Number Conjecture possibly Palindromic number conjecture ( wikisearch; web; books)
13. Pancake Cutting possibly Pancake cutting ( wikisearch; web; books)

1. Pandiagonal Perfect Magic Cube possibly Pandiagonal perfect magic cube ( wikisearch; web; books)
2. Pandiagonal Semiperfect Magic Cube possibly Pandiagonal semiperfect magic cube ( wikisearch; web; books)
3. Pandiagonal Square possibly Pandiagonal square ( wikisearch; web; books)
4. Pandigital Fraction possibly Pandigital fraction ( wikisearch; web; books)
5. Pap adjoint theorem ( wikisearch; web; books)
6. Pappus axiom ( wikisearch; web; books)
7. Pappus's Harmonic Theorem possibly Pappus's harmonic theorem ( wikisearch; web; books)
8. Paquerette de Mélibée possibly Paquerette de mélibée or Paquerette de méLibée ( wikisearch; web; books)