OPENJYOTISH PRIMER, CHAPTER 1: GRAHAS, RASIS, BHAVAS, NAKSHATRAS
================================================================
Original synthesis by the OpenJyotish contributors (AGPL-3.0, like the
program). Not copied from any book: every rule below is either classical
doctrine traceable to the public-domain texts in this folder (Iyer's
Brihat Jataka 1885 / Brihat Samhita 1884, Burgess's Surya Siddhanta
1860, Sastri's Siddhanta Siromani 1861) or a description of this
program's own computations (dignities, lords and nakshatra mapping match
the engine exactly — check them with `jhora dignities` style outputs,
the Planets tab, or the verification notes under AI answers).

Conventions used everywhere in this program: longitudes are sidereal
(Lahiri ayanamsa); signs are numbered Aries 0 to Pisces 11; houses
H1..H12 count whole signs forward from the lagna.


1. THE NINE GRAHAS
------------------
A graha ("seizer") is a significator: each planet signifies outer topics
and inner faculties at once. Rahu and Ketu are shadow points (the lunar
nodes), treated as full grahas except that they own no sign and never
retrograde in the usual sense. Saturn, Jupiter and Mars are natural
malefics; Venus, Mercury (when joined to benefics), Jupiter and the
waxing Moon are natural benefics; Sun is a mild malefic, Rahu/Ketu are
malefic by nature.

SUN (Surya) — soul, father, authority, vitality, profession. Rules Leo.
Exalted Aries 10°, debilitated Libra 10°, moolatrikona Leo 0–20°.
Strong Sun: self-direction, command, immunity. Weak Sun: fragile
authority, conflict with father figures and governments.

MOON (Chandra) — mind, mother, emotions, fluids, public. Rules Cancer.
Exalted Taurus 3°, debilitated Scorpio 3°, moolatrikona Taurus 3–30°.
Strong Moon: emotional stability, memory, popularity. Weak or waning
Moon: restlessness, anxiety, variable fortune. The Moon's nakshatra
fixes the Vimshottari dasha sequence at birth.

MARS (Mangala) — energy, siblings, courage, property, blood. Rules
Aries and Scorpio. Exalted Capricorn 28°, debilitated Cancer 28°,
moolatrikona Aries 0–12°. Strong Mars: initiative, athleticism,
engineering skill. Afflicted Mars: accidents, quarrels, surgical
events; its affliction of Moon or lagna is Kuja Dosha.

MERCURY (Budha) — speech, intellect, commerce, skin, nerves. Rules
Gemini and Virgo. Exalted Virgo 15° (also its own and moolatrikona
Virgo 15–30°), debilitated Pisces 15°. Strong Mercury: analysis,
languages, trade. Weak Mercury: nervous disorders, confused speech,
unreliable agreements.

JUPITER (Guru) — wisdom, children, dharma, wealth, counsel. Rules
Sagittarius and Pisces. Exalted Cancer 5°, debilitated Capricorn 5°,
moolatrikona Sagittarius 0–5°. Strong Jupiter: judgment, progeny,
fortune through counsel. Weak Jupiter: poor advice, liver complaints,
losses through misplaced trust.

VENUS (Shukra) — love, spouse, luxury, vehicles, arts, semen. Rules
Taurus and Libra. Exalted Pisces 27°, debilitated Virgo 27°,
moolatrikona Libra 0–15°. Strong Venus: comfort, artistic taste,
harmonious marriage. Weak Venus: indulgence, renal/venereal complaints,
vehicle troubles.

SATURN (Shani) — discipline, longevity, sorrow, service, lands. Rules
Capricorn and Aquarius. Exalted Libra 20°, debilitated Aries 20°,
moolatrikona Aquarius 0–20°. Strong Saturn: endurance, organization,
gains through persistence. Weak Saturn: chronic delay, melancholy,
servitude, bone and joint complaints.

RAHU — obsession, foreigners, technology, smoke, sudden events. Owns no
sign (co-lords Aquarius in some schools, which this program does not
use for dignity). Exaltation debated between Taurus and Scorpio; the
engine assigns no exaltation dignity to the nodes. Strong Rahu:
worldly rise, technical skill. Afflicted Rahu: confusion, poisoning,
scandal, breaks in routine.

KETU — detachment, spirituality, moksha, past karma, flags and wounds.
Owns no sign. Strong Ketu: insight, renunciation, research ability.
Afflicted Ketu: aimlessness, mysterious ailments, severances. Ketu
Mahadasha spiritualizes whatever house it occupies.

Dignity ladder used by this program, strongest to weakest: exalted,
moolatrikona, own sign, friendly sign, neutral, inimical sign,
debilitated. Declared dignities are always positional facts, never
moral judgments.


2. THE TWELVE RASIS
-------------------
Each rasi is 30°. Lord, element and rhythm never change:

Aries (Mesha) — Mars — fire — movable (chara) — odd.
Taurus (Vrishabha) — Venus — earth — fixed (sthira) — even.
Gemini (Mithuna) — Mercury — air — dual (dvisva) — odd.
Cancer (Karka) — Moon — water — movable — even.
Leo (Simha) — Sun — fire — fixed — odd.
Virgo (Kanya) — Mercury — earth — dual — even.
Libra (Tula) — Venus — air — movable — odd.
Scorpio (Vrishchika) — Mars — water — fixed — even.
Sagittarius (Dhanus) — Jupiter — fire — dual — odd.
Capricorn (Makara) — Saturn — earth — movable — even.
Aquarius (Kumbha) — Saturn — air — fixed — odd.
Pisces (Meena) — Jupiter — water — dual — even.

Fire signs act, earth signs build, air signs connect, water signs feel.
Movable signs initiate, fixed signs sustain, dual signs adapt. Odd signs
are assertive (positively polarized), even signs receptive.


3. THE TWELVE BHAVAS
--------------------
Houses count whole signs forward from the lagna: H1 is the lagna's sign,
H2 the next, and so on. Each bhava signifies:

H1 Tanu — self, body, temperament, overall vitality.
H2 Dhana — wealth, speech, family, food.
H3 Sahaja — siblings, courage, short journeys, hands.
H4 Bandhu — mother, home, vehicles, education foundations.
H5 Putra — children, intellect, romance, speculation, mantra.
H6 Shatru — enemies, disease, debt, service, litigation.
H7 Kalatra — spouse, partnerships, contracts, travel abroad.
H8 Randhra — longevity, obstacles, inheritance, occult, surgery.
H9 Bhagya — fortune, dharma, father, guru, long journeys.
H10 Karma — profession, status, authority, public acts.
H11 Labha — gains, elder siblings, networks, ambitions.
H12 Vyaya — loss, expenses, foreign residence, bed pleasures, moksha.

The lord of each house carries its affairs wherever it sits: the 9th
lord in the 7th, for example, links fortune with partnership (a Dhana
Yoga pattern the program detects automatically).


4. THE 27 NAKSHATRAS
--------------------
The zodiac is also divided into 27 lunar mansions of 13°20' each,
starting Ashwini at Aries 0°. Each has four padas (quarters) of 3°20'
and a Vimshottari lord cycling Ketu, Venus, Sun, Moon, Mars, Rahu,
Jupiter, Saturn, Mercury — three full cycles. Order with lords:

Ashwini (Ketu), Bharani (Venus), Krittika (Sun), Rohini (Moon),
Mrigashira (Mars), Ardra (Rahu), Punarvasu (Jupiter), Pushya (Saturn),
Ashlesha (Mercury), Magha (Ketu), Purva Phalguni (Venus),
Uttara Phalguni (Sun), Hasta (Moon), Chitra (Mars), Swati (Rahu),
Vishakha (Jupiter), Anuradha (Saturn), Jyeshtha (Mercury), Mula (Ketu),
Purva Shadha (Venus), Uttara Shadha (Sun), Shravana (Moon),
Dhanishta (Mars), Shatabhisha (Rahu), Purva Bhadrapada (Jupiter),
Uttara Bhadrapada (Saturn), Revati (Mercury).

The Moon's nakshatra at birth selects the running Vimshottari Mahadasha
and the balance remaining in it; the program computes both exactly
(`dasa` command, Dasas tab). Nakshatra placement refines every graha
reading: a planet acts through its sign for gross results and through
its nakshatra lord for subtle ones.


5. READING THEM TOGETHER (WORKED EXAMPLE)
-----------------------------------------
Reference chart used across the test suite: 1990-01-15, 17:30 IST,
Bangalore (12.97N 77.59E). Computed positions (Lahiri):

Lagna Gemini 82.6°. Sun Capricorn (Uttara Shadha-2). Moon Leo
(Purva Phalguni-4). Mars Scorpio (Jyeshtha-3). Mercury Sagittarius
(Purva Shadha-2). Jupiter Gemini (Ardra-1). Venus Capricorn
(Uttara Shadha-4). Saturn Sagittarius (Purva Shadha-4).

Read it mechanically:
- Lagna lord Mercury sits in H7 (Sagittarius) — self-definition through
  partnership; Mercury in a dual fire sign: adaptive, outspoken.
- Moon in Leo H3 (Purva Phalguni, Venus-ruled quarter): mind seeking
  recognition among siblings/peers; Venus colors the emotions.
- Mars in Scorpio H6 (Jyeshtha): own sign in the house of conflict —
  fights and wins disputes; watch accidents.
- Jupiter in Gemini H1 (Ardra): wisdom placed in self, but Ardra's Rahu
  lordship gives unconventional, storm-tested intellect.
- Sun and Venus both in Capricorn H8 (Uttara Shadha): identity and love
  operating through other people's resources, crises and research.
- Saturn in Sagittarius H7: discipline demanded inside partnership.

Every sentence above is checkable: reproduce this chart with
`jhora chart "1990-01-15 17:30:00 +0530 12.9716 77.5946"` and compare
each longitude, sign, house and nakshatra against the program's Planets
table. Where this chapter and the program ever disagree, the program's
computed values win — report it as a bug.


6. WHERE EACH FACT LIVES IN THE PROGRAM
---------------------------------------
Graha positions/signs/nakshatras: Planets tab, `jhora chart`, `analyze`.
Dignities: Strengths tab, Shadbala/Vimsopaka tables. Houses: Houses tab
(`H1..H12` whole-sign from lagna). Nakshatra lords and dasha balance:
Dasas tab, `jhora dasa`. Karaka roles: Arudha & Karaka tab. Lords of
houses: Houses tab lord column. AI answers rephrase exactly these
numbers; the verification note under each answer confirms them.
